Ligandrol
![]() | |
Clinical data | |
---|---|
Other names | LGD4033; VK5211; VK-5211; Ligandrol; Anabolicum |
Routes of administration | By mouth[1][2] |
ATC code |
|
Legal status | |
Legal status | |
Pharmacokinetic data | |
Elimination half-life | 24–36 hours[3][2][4] |
Identifiers | |
| |
CAS Number | |
PubChem CID | |
DrugBank | |
ChemSpider | |
UNII | |
ChEMBL | |
CompTox Dashboard (EPA) | |
Chemical and physical data | |
Formula | C14H12F6N2O |
Molar mass | 338.253 g·mol−1 |
3D model (JSmol) | |
| |
|
LGD-4033, also known by the developmental code name VK5211 and by the black-market name Ligandrol, is a selective androgen receptor modulator (SARM) which is under development for the treatment of muscle atrophy in people with hip fracture.[5] It was also under development for the treatment of cachexia, hypogonadism, and osteoporosis, but development for these indications was discontinued.[5] LGD-4033 has been reported to dose-dependently improve lean body mass and muscle strength in preliminary clinical trials, but is still being developed and has not been approved for medical use.[5][6][7][8] The drug is taken by mouth.[1][2]
Known possible side effects of LGD-4033 include headache, dry mouth, adverse lipid changes like decreased high-density lipoprotein (HDL) cholesterol levels, changes in sex hormone concentrations like decreased testosterone levels, elevated liver enzymes, and liver toxicity.[9][1][10][3][2][11][6] The potential of LGD-4033 and other SARMs for producing masculinization is largely uncharacterized and hence is unknown.[3] LGD-4033 is a nonsteroidal SARM, acting as an agonist of the androgen receptor (AR), the biological target of androgens and anabolic steroids like testosterone and dihydrotestosterone (DHT).[10] However, it shows dissociation of effect between tissues in preclinical studies, with agonistic and anabolic effects in muscle and bone and partially agonistic or antagonistic effects in the prostate gland.[12][3][13]
LGD-4033 was first described in 2010.[12][4] It is less clinically studied than other SARMs like enobosarm, with only a few small clinical trials having been conducted and reported.[14][11][9][2][8] LGD-4033 has not yet completed clinical development or been approved for any use.[5][10][3] As of 2023, it is in phase 2 clinical trials for the treatment of hip fracture and muscle atrophy.[5] LGD-4033 was developed by Ligand Pharmaceuticals, and is now being developed by Viking Therapeutics.[5]
Aside from its development as a potential pharmaceutical drug, LGD-4033 is on the World Anti-Doping Agency list of prohibited substances[15] and is sold for physique- and performance-enhancing purposes by black-market Internet suppliers.[3][9] LGD-4033 is often used in these contexts at doses greatly exceeding those evaluated in clinical trials, with unknown effectiveness and safety.[3][9] Many products sold online that are purported to be LGD-4033 either contain none or contain other unrelated substances.[3][16] Social media has played an important role in facilitating the widespread non-medical use of SARMs.[17]
Medical uses
[edit]LGD-4033 is not approved for any medical use and is not available as a licensed pharmaceutical drug as of 2023.[5][10][3]
Side effects
[edit]Side effects of LGD-4033 may include headache and dry mouth.[9] LGD-4033 has been found to dose-dependently decrease levels of total testosterone, free testosterone, follicle-stimulating hormone (FSH), sex hormone-binding globulin (SHBG), HDL cholesterol, and triglycerides, while not affecting levels of luteinizing hormone (LH), total cholesterol, LDL cholesterol, or prostate-specific antigen (PSA).[3][2] Due to the decreased ratio of HDL cholesterol to LDL cholesterol, LGD-4033 could theoretically increase the risk of heart attack and stroke.[18]
Elevated liver enzymes, such as increased levels of aspartate aminotransferase (AST) or alanine aminotransferase (ALT), have not been reported with LGD-4033 in the few conducted clinical trials thus far.[6][9] However, multiple case reports of hepatotoxicity with LGD-4033 in the setting of non-medical use have been published.[11][6][9][19]
LGD-4033 and other SARMs are largely uncharacterized in terms of their potential for masculinizing effects, for example in women.[3] In addition, the effects and safety of high doses of LGD-4033 and other SARMs, which are often used in non-medical contexts, are unknown.[3] Anecdotal reports of masculinization with black-market SARMs in women exist in online forums.[17]
The United States Food and Drug Administration (FDA) claims that "liver toxicity, adverse effects on blood lipid levels, and a potential to increase the risk of heart attack and stroke" are among the potential adverse health effects of SARMs including LGD-4033.[20]
Overdose
[edit]LGD-4033 has been assessed in clinical trials at single doses ranging from 0.1 to 22 mg and at repeated doses ranging from 0.1 to 2 mg/day for 3 to 12 weeks.[11] The drug sold via black-market Internet suppliers and used non-medically is often taken at much higher doses than those used in repeated-dose clinical trials (e.g., 5–10 mg/day), with unknown adverse effects and risks.[3][9][11]
Pharmacology
[edit]Pharmacodynamics
[edit]LGD-4033 is a selective androgen receptor modulator (SARM), or a tissue-selective mixed agonist or partial agonist of the androgen receptor (AR).[10] This receptor is the biological target of endogenous androgens like testosterone and dihydrotestosterone (DHT) and of synthetic anabolic steroids like nandrolone and oxandrolone.[21][22][23] LGD-4033 shows high affinity and selectivity for the AR, with an affinity (Ki) value of 0.9 nM.[12][3][13] It did not meaningfully interact with the progesterone receptor, glucocorticoid receptor, or mineralocorticoid receptor (all Ki > 4,000 nM), whereas the estrogen receptor
LGD-4033 has shown robust selectivity for stimulation of the levator ani muscle relative to stimulation of the prostate in rats.[12] At the highest assessed dose in castrated male rats, levator ani weight was increased to around 140% of that of gonadally intact controls, whereas prostate weight was only increased to around 45% of that of intact controls.[13] The tissue selectivity of LGD-4033 was independent of local tissue drug concentration, suggesting that its selectivity was intrinsic.[12][13] The muscle-stimulating effects of LGD-4033 have also been confirmed in humans in preliminary clinical trials.[10][26] The data also allow comparison between different SARMs and other AR agonists.[10][26] In a phase 1 clinical trial in 76 healthy young men, 1 mg/day LGD-4033 increased lean body mass by 1.2 kg after 3 weeks of treatment.[10][26][2] For comparison, enobosarm, another SARM, increased lean body mass by 1.3 kg at a dose of 3 mg/day after 12 weeks in healthy elderly men and postmenopausal women.[2][26][27] It was concluded that the employed dose of LGD-4033 produced similar increases in lean body mass compared to enobosarm despite a substantially shorter treatment period.[2] In a phase 2 clinical trial in 108 women and men with hip fracture, LGD-4033 increased lean body mass by 4.8% at 0.5 mg/day, 7.2% at 1 mg/day, and 9.1% at 2 mg/day after 12 weeks of treatment.[8] For comparison, lean body mass with enobosarm 3 mg/day after the same time period of 12 weeks increased by about 0.30% at 0.1 mg/day, 0.40% at 0.3 mg/day, 1.2% at 1 mg/day, and 3.1% at 3 mg/day, with only the latter change achieving statistical significance.[27] Relative to SARMs, supraphysiological doses of testosterone (300–600 mg/week intramuscular testosterone enanthate) over similar timeframes, like 20 weeks, have been found to result in lean body mass gains of 5 to 8 kg in healthy young men.[28][3][29]
In addition to selectivity for muscle and bone over the prostate gland, LGD-4033 has also been stated by Ligand Pharmaceuticals researchers to have reduced strength in the sebaceous glands.[12][4] Reduced activity in stimulating sebaceous gland formation, to about 30 to 50% of that produced by DHT at doses with similar anabolic potency in rats, has also been reported for certain other SARMs, like the steroidal agents TFM-4AS-1 and MK-0773.[12] In addition, enobosarm and MK-0773 have been reported to limitedly stimulate the sebaceous glands in small short-term clinical studies in women.[30][27][31]
Pharmacokinetics
[edit]LGD-4033 showed linear or dose-proportional pharmacokinetics across doses of 0.1 to 1 mg/day over 21 days of administration.[2] Levels of LGD-4033 were 3-fold higher at day 21 compared to day 1, indicating significant accumulation with repeated administration.[2] The mean area-under-curve levels of LGD-4033 on day 21 were 19 ng•day/mL at 0.1 mg/day, 85 ng•day/mL at 0.3 mg/day, and 238 ng•day/mL at 1 mg/day.[2] The elimination half-life of LGD-4033 is 24 to 36 hours.[3][2][4] Pharmacokinetic studies of LGD-4033 for purposes of doping detection have also been conducted.[32][33][34][35]
Chemistry
[edit]LGD-4033 is a nonsteroidal SARM with a pyrrolidinyl-benzonitrile core structure and is also referred to as a quinoline or quinolinone SARM.[3][12] LG121071 (LGD-121071), a tricyclic quinoline, was the predecessor compound of LGD-4033.[10] The chemical structure of LGD-4033 had not been disclosed as late as 2013.[12][26] LGD-4033 has sometimes been confused with other structurally related Ligand Pharmaceuticals SARMs including LGD-2226, LGD-2941, and LGD-3303,[10][5] but is a different compound from these agents.[12][10]
LGD-4033 is a small-molecule (molecular weight = 338.3 g/mol) and highly lipophilic (predicted log P = 3.6–3.7) compound.[36][37]
History
[edit]The predecessor of LGD-4033, LG121071 (LGD-121071), was discovered by Ligand Pharmaceuticals and was first described in the literature in January 1999.[10][38] It was the first orally active nonsteroidal androgen receptor agonist to be discovered.[39][38] LG121071 is a tricyclic quinoline derivative, and is structurally distinct from arylpropionamide SARMs like andarine and enobosarm (ostarine).[39] LGD-2226, a bicyclic quinoline SARM, was subsequently developed by Ligand Pharmaceuticals and TAP Pharmaceuticals in 2001.[39] Other quinoline SARMs, like LGD-2941 and LGD-3303, were also subsequently developed by Ligand Pharmaceuticals prior to the development of LGD-4033.[12][40]
LGD-4033 was developed by Ligand Pharmaceuticals and was first described in the literature in 2010.[5][12][4] On the basis of a favorable preclinical profile, phase 1 clinical trials of LGD-4033 began in 2009.[12] The results of a single-dose phase 1 clinical trial were published as a conference abstract in 2010 and the findings of a multi-dose phase 1 trial were published as a journal article in 2013.[11][1][4][2] A third phase 1 trial was also conducted.[6][14] By 2012, a phase 2 trial of LGD-4033 for the treatment of muscle wasting related to cancer cachexia, acute rehabilitation (e.g., hip fracture), and acute illness was being prepared by Ligand Pharmaceuticals.[12][1] On 22 May 2014, Viking Therapeutics licensed the developmental rights of LGD-4033 from Ligand Pharmaceuticals and intended to advance the compound into mid-to-late-stage clinical trials.[10] The phase 2 study of LGD-4033 for muscle wasting was finally initiated in November 2016[41] and was completed with results reported in 2017 and 2018.[14][10][8] As of March 2023, LGD-4033 (VK5211) continues to be under development by Viking Therapeutics and continues to be in phase 2 clinical trials for treatment of muscle atrophy and hip fracture.[5]
Society and culture
[edit]Regulatory information
[edit]In the United States, LGD-4033 is an Investigational New Drug and is not approved for any medical use.[5]
Non-medical use
[edit]Though not an approved drug, LGD-4033 (Ligandrol) has been sold on the black market in countries where it is classified as an illegal substance.[42][43] Along with enobosarm (ostarine; GTx-024, S-22), andarine (GTx-007; S-4), and vosilasarm (RAD140; "testolone"), LGD-4033 is one of the most popular and common non-medically-used SARMs.[9][44] Many products sold online that are purported to be LGD-4033 either contain none or contain other unrelated substances, and doses are also frequently not as labeled.[3][16] Social media has played an important role in facilitating the widespread non-medical use of SARMs.[17]
On 23 October 2017, a nutritional supplement company in Missouri called Infantry Labs was warned by the FDA that the distribution of two of its products violated the Federal Food, Drug, and Cosmetic Act. One of the substances was LGD-4033. The company advertised as benefits of the LGD-4033: "increases in lean body mass and decrease in body fat" and "increases in strength, well being, as well as healing possibilities". The company mislabeled as "dietary supplements" what should have been "new drugs" or "prescription drugs" and were instructed to document the steps they would take in order to cease the violation.[20]
Also on 23 October 2017, the FDA sent a warning letter to a New Jersey company called Panther Sports Nutrition. The company's marketing approach for the product was similar to that of the Infantry Labs case, and the product was advertised as a "mass builder" and "physique enhancing agent".[45]
Doping in sport
[edit]LGD-4033 is on the World Anti-Doping Association (WADA) list of prohibited drugs[15] and has been found in drug testing samples of some athletes.[46] Since at least June 2015, LGD-4033 has been available via the internet. In that month, German scientists proposed a new test to detect its metabolites present in human urine, and suggested an expansion of the WADA regime.[47] LGD-4033 has been found in WADA samples and in racehorses as well.[48]
List of doping cases
[edit]On 15 March 2014 cyclist Christos Volikakis was informed of an Adverse Analytical Finding on a re-analysis of a sample from the 2016 Rio Olympics. The athlete has since requested an analysis of the B sample.[49]
In 2015, the quarterback of the Florida Gators, Will Grier, was suspended for testing positive for LGD-4033, a claim that the University of Florida denies.[50]
In 2017, Joakim Noah was banned for twenty games by the NBA for testing positive for LGD-4033.[51]
In 2019, Australian swimmer Shayna Jack tested positive for LGD-4033. She denies knowingly taking the substance.[52]
In August 2019, it came to light that Canadian sprint canoeist Laurence Vincent Lapointe tested positive for LGD-4033; the athlete denies knowingly taking a forbidden substance that resulted in her suspension from competition. The athlete remarked that the National Team Training Centre purchased nutritional supplements for its athletes and denied buying or taking nutritional supplements on her own. [53] On January 27, 2020, she was cleared of all charges. The substance was found in her results because of an exchange of bodily fluids with her boyfriend, who took LGD-4033.[54]
In January 2020, Chilean ATP tennis singles competitor Nicolás Jarry tested positive for both LGD-4033 and stanozolol. He protested at the time that the multi-vitamins from Brazil that he took on the advice of an unnamed doctor were contaminated.[55]
On 3 September 2022, sprinter Nzubechi Grace Nwokocha was provisionally suspended for the use of banned substances enobosarm and LGD-4033[56] by the Athletics Integrity Unit (AIU).
On 23 January 2024, Tristan Thompson was suspended for 25 games by the NBA for testing positive for ibutamoren and LGD-4033.[57]
On 12 March 2024, curler Briane Harris was provisionally suspended for up to four years after testing positive for LGD-4033. She denies this after being tested by doping control officers on Jan. 24 and notified of her positive test on Feb. 15. A second sample, called the B sample, also confirmed the positive test. She plans to appeal the ban to the Court of Arbitration for Sport, arguing she was unknowingly exposed to it through bodily contact. [58]
Research
[edit]Oral administration of LGD-4033 to cynomolgus monkeys at daily doses varying from 0 to 75 mg/kg over 13 weeks demonstrated significant body weight gain in both males and females. After 48 days, the 75 mg/kg dose testing was halted due to toxicity concerns, but this did not negatively impact development of the drug as this dose is significantly higher than the doses being utilized in a phase 2 clinical trial.[59]
Two phase 1 clinical trials of LGD-4033 have been conducted and reported.[11] The first was a single-dose study published as a conference abstract in 2010 and the second was a multi-dose study published as a journal article in 2013.[11][4][2] The multi-dose phase 1 trial published in 2013 reported that LGD-4033 dose-dependently improved lean body mass and muscle strength in 76 healthy young men over 21 days.[2] It was generally well-tolerated in this study, with no significant adverse effects reported.[2]
A phase 2 clinical trial, initiated on 3 November 2016, consisted of 108 women and men recovering from hip fracture surgery.[8] The randomized study participants received either placebo or varying doses of LGD-4033 over a period of 12 weeks, with improved lean body mass as the primary endpoint.[8] Other endpoints included satisfactory results in terms of quality of life, safety, and pharmacokinetics.[41] This study was completed and results reported in 2017 and 2018.[14][10][8] In the trial, LGD-4033 dose-dependently improved lean body mass and muscle strength and was reported to be safe and well-tolerated.[6][7][8] Placebo-adjusted lean body mass was increased by 4.8% at 0.5 mg/day, 7.2% at 1 mg/day, and 9.1% at 2 mg/day after 12 weeks.[8]
As of 2023, LGD-4033 has been less studied than other SARMs like enobosarm, with only three small phase 1 clinical trials and one phase 2 trial, or a total of four clinical studies, having been conducted and reported.[14][11][9][2][8]
References
[edit]- ^ a b c d e Choi SM, Lee BM (2015). "Comparative safety evaluation of selective androgen receptor modulators and anabolic androgenic steroids". Expert Opin Drug Saf. 14 (11): 1773–85. doi:10.1517/14740338.2015.1094052. PMID 26401842. S2CID 8104778.
- ^ a b c d e f g h i j k l m n o p q r Basaria S, Collins L, Dillon EL, Orwoll K, Storer TW, Miciek R, et al. (January 2013). "The safety, pharmacokinetics, and effects of LGD-4033, a novel nonsteroidal oral, selective androgen receptor modulator, in healthy young men". J Gerontol A Biol Sci Med Sci. 68 (1): 87–95. doi:10.1093/gerona/gls078. PMC 4111291. PMID 22459616.
- ^ a b c d e f g h i j k l m n o p q r s Machek SB, Cardaci TD, Wilburn DT, Willoughby DS (December 2020). "Considerations, possible contraindications, and potential mechanisms for deleterious effect in recreational and athletic use of selective androgen receptor modulators (SARMs) in lieu of anabolic androgenic steroids: A narrative review". Steroids. 164: 108753. doi:10.1016/j.steroids.2020.108753. PMID 33148520. S2CID 225049089.
- ^ a b c d e f g Meglasson MD, Kapil R, Leibowitz MT, Peterkin JJ, Chen Y, Lee KJ, et al. (2010). "P8-2-7 Phase I clinical trial of LGD-4033, a novel selective androgen receptor modulator (SARM)". Endocrine Journal. 57 (Suppl 2 [14th International Congress of Endocrinology (ICE 2010), March 26-30, 2010, Kyoto, Japan]): S542. doi:10.1507/endocrj.57.S355. ISSN 0918-8959.
LGD-4033 is a potent SARM that binds the human androgen receptor with Kd =0.9 nM. In animal models, it has anabolic effects on skeletal muscle and bone, but spares prostate, sebaceous glands, and female genitalia. In a double-blind, placebo-controlled, first-in-human Phase I trial, ascending single oral doses of LGD-4033 ranging from 0.1 mg to 22 mg were administered to healthy males. LGD4033 was safe and well tolerated up to the highest tested dose with no serious adverse events reported. LGD-4033 exhibited dose-proportional, sustained systemic exposure (AUC0-48hr: 24 to 7000 ng. hr/ mL for 0.1 and 22 mg doses, respectively). The elimination half-life (t1/2) was 31 hrs, indicating LGD-4033 is amenable for once daily dosing. PK-PD studies were conducted in orchiectomized (ORDX) rats, a model of androgen action, to determine the LGD-4033 efficacious exposure level. Subcutaneous minipumps were used to mimic the 10-fold longer t1/2 in humans vs. rats. A dose that produced an
AU C of 80 ng. hr/mL restored the atrophied muscle mass of ORDX rats to the eugonadal level (270% increase in levator ani muscle weight with LGD-4033 vs. vehicle) and reduced the elevated luteinizing hormone level of ORDX rats by 98%. The efficacious range predicted by the preclinical model will be achieved by repeated daily doses ca. 0.25 mg in humans. Conclusion: LGD-4033 is a well-tolerated and highly tissue-specific, potential new treatment for sarcopenia (e.g., cancer cachexia or the frail elderly) and osteoporosis that is predicted to be effective using low, daily oral doses. A Phase I multi-dose study is in progress. - ^ a b c d e f g h i j k "VK 5211 - AdisInsight".
- ^ a b c d e f Mohideen H, Hussain H, Dahiya DS, Wehbe H (February 2023). "Selective Androgen Receptor Modulators: An Emerging Liver Toxin". J Clin Transl Hepatol. 11 (1): 188–196. PMC 9647117. PMID 36479151.
- ^ a b Girgis CM (2019). "Sex Steroid Hormones and Osteosarcopenia". Osteosarcopenia: Bone, Muscle and Fat Interactions. Cham: Springer International Publishing. pp. 173–190. doi:10.1007/978-3-030-25890-0_8. ISBN 978-3-030-25889-4. S2CID 209246318.
Other molecules have been developed including LGD-4033 which increased muscle mass and strength in healthy males after 3 weeks (Basaria et al. 2013) [...] Recently, a phase 2 trial on the agent VK211 demonstrated dose-dependent increases in lean body mass, and improvements in physical performance in patients who had sustained hip fracture (Ristic et al. 2018). Whilst SARMs hold great promise as anabolic agents that may offer an effective therapy for osteosarcopenia, long-term side effects of these agents are unknown, studies are generally small and of short duration. Regulation of these products poses immense challenges with their high uptake on the black market and via the internet as performance-enhancing, body-building agents, which may overshadow their potential mainstream application in disorders of aging.
- ^ a b c d e f g h i j Ristic B, Harhaji V, Sirbu PD, Irizarry-Roman M, Bucs G, Sztanyi I, et al. (2018). "1072 VK5211, a novel selective androgen receptor modulator (SARM), significantly improves lean body mass in hip fracture patients: results of a 12 week phase 2 trial". Journal of Bone and Mineral Research. 33 (Suppl 1 [2018 Annual Meeting of the American Society for Bone and Mineral Research Palais des congrès de Montréal in Montréal, Quebéc, Canada September 28 – October 1, 2018]): S24. doi:10.1002/jbmr.3621. PMID 30444937.
Introduction Hip fractures are a leading cause of disability and morbidity in older people. Post-facture, an increased catabolic state often leads to loss of muscle, which can impair balance and endurance, potentially increasing the risk of further injury. Anabolic steroids have been shown to improve muscle mass in certain settings. Selective androgen receptor modulators (SARMs) could be similarly effective in older patients who have suffered muscle loss following hip fracture, while potentially avoiding undesired side effects associated with broad-acting anabolic agents. VK5211 is a novel, non-steroidal, orally available SARM that has been shown to improve muscle mass and bone mineral density in animal models. In humans, a prior Phase 1 study demonstrated increases in lean body mass after 21 days of dosing. Purpose A 12 week study was conducted to assess the safety and efficacy of VK5211 in patients who had suffered a hip fracture. Methods A randomized, double-blind, placebo-controlled, multicenter, international Phase 2 trial was conducted to evaluate VK5211 in patients recovering from hip fracture. Patients were randomized to receive daily oral VK5211 doses of 0.5 mg, 1.0 mg, 2.0 mg, or placebo, for 12 weeks. The primary endpoint evaluated change from baseline in lean body mass, less head, in patients receiving VK5211 compared with placebo. Secondary and exploratory endpoints included changes in appendicular lean mass, bone density, and functional performance. Results A total of 108 patients were randomized (83 F, 25 M; mean age 77). Patients receiving VK5211 demonstrated significant increases in lean body mass, less head, after 12 weeks. Placebo-adjusted increases were 4.8% at 0.5 mg, 7.2% at 1.0 mg, and 9.1% at 2.0 mg (p < 0.005 for each). The proportions of patients experiencing at least a 2.0 kg increase were 14% with placebo, 57% at 0.5 mg, 65% at 1.0 mg, and 81% at 2.0 mg (p < 0.01 for each). Patients receiving VK5211 demonstrated improvement in certain measures of functional performance, including the 6-minute walk test and short physical performance battery (these endpoints were not powered for significance). The rates of adverse events were similar in cohorts receiving VK5211 as compared with placebo, and no drug-related SAEs were observed in VK5211-treated patients. Conclusion VK5211 was well-tolerated and produced improvements in lean body mass in hip fracture patients following 12 weeks of dosing. Further evaluation in this setting is warranted.
- ^ a b c d e f g h i j Hall E, Vrolijk MF (July 2023). "Androgen Receptor and Cardiovascular Disease: A Potential Risk for the Abuse of Supplements Containing Selective Androgen Receptor Modulators". Nutrients. 15 (15): 3330. doi:10.3390/nu15153330. PMC 10420890. PMID 37571268.
- ^ a b c d e f g h i j k l m n o Fonseca GW, Dworatzek E, Ebner N, Von Haehling S (August 2020). "Selective androgen receptor modulators (SARMs) as pharmacological treatment for muscle wasting in ongoing clinical trials". Expert Opin Investig Drugs. 29 (8): 881–891. doi:10.1080/13543784.2020.1777275. PMID 32476495. S2CID 219174372.
- ^ a b c d e f g h i Vignali JD, Pak KC, Beverley HR, DeLuca JP, Downs JW, Kress AT, et al. (May 2023). "Systematic Review of Safety of Selective Androgen Receptor Modulators in Healthy Adults: Implications for Recreational Users". J Xenobiot. 13 (2): 218–236. doi:10.3390/jox13020017. PMC 10204391. PMID 37218811.
- ^ a b c d e f g h i j k l m n o p Zhang X, Sui Z (February 2013). "Deciphering the selective androgen receptor modulators paradigm". Expert Opin Drug Discov. 8 (2): 191–218. doi:10.1517/17460441.2013.741582. PMID 23231475. S2CID 2584722.
- ^ a b c d e f g Vajda EG, Marschke K, van Oeveren A, Zhi L, Chang WY, López FJ, et al. (2009), "LGD-4033 builds muscle and bone with reduced prostate activity and may be beneficial in age-related frailty" (PDF), Proceedings of the 62nd Annual Meeting of the Gerontology Society of America, November 11-21, 2009, Atlanta, Georgia
- ^ a b c d e "VK5211". Viking Therapeutics.
- ^ a b "Prohibited List". World Anti Doping Agency. 2014-07-22.
- ^ a b Van Wagoner RM, Eichner A, Bhasin S, Deuster PA, Eichner D (November 2017). "Chemical Composition and Labeling of Substances Marketed as Selective Androgen Receptor Modulators and Sold via the Internet". JAMA. 318 (20): 2004–2010. doi:10.1001/jama.2017.17069. PMC 5820696. PMID 29183075.
- ^ a b c Hahamyan HA, Vasireddi N, Voos JE, Calcei JG (August 2023). "Social media's impact on widespread SARMs abuse". Phys Sportsmed. 51 (4): 291–293. doi:10.1080/00913847.2022.2078679. PMID 35574698.
- ^ Tauchen J, Jurášek M, Huml L, Rimpelová S (February 2021). "Medicinal Use of Testosterone and Related Steroids Revisited". Molecules. 26 (4): 1032. doi:10.3390/molecules26041032. PMC 7919692. PMID 33672087.
- ^ Leciejewska N, Jędrejko K, Gómez-Renaud VM, Manríquez-Núñez J, Muszyńska B, Pokrywka A (December 2023). "Selective androgen receptor modulator use and related adverse events including drug-induced liver injury: Analysis of suspected cases". Eur J Clin Pharmacol. 80 (2): 185–202. doi:10.1007/s00228-023-03592-3. PMC 10847181. PMID 38059982.
- ^ a b "WARNING LETTER Infantry Labs LLC MARCS-CMS 535333 — OCT 23, 2017". FDA. 23 October 2017.
- ^ Wu C, Kovac JR (October 2016). "Novel Uses for the Anabolic Androgenic Steroids Nandrolone and Oxandrolone in the Management of Male Health". Curr Urol Rep. 17 (10): 72. doi:10.1007/s11934-016-0629-8. PMID 27535042. S2CID 43199715.
- ^ a b Mohler ML, Nair VA, Hwang DJ, Rakov IM, Patil R, Miller DD (2005-10-28). "Nonsteroidal tissue selective androgen receptor modulators: a promising class of clinical candidates". Expert Opinion on Therapeutic Patents. 15 (11). Informa Healthcare: 1565–1585. doi:10.1517/13543776.15.11.1565. ISSN 1354-3776. S2CID 96279138.
- ^ a b Kicman AT (June 2008). "Pharmacology of anabolic steroids". Br J Pharmacol. 154 (3): 502–21. doi:10.1038/bjp.2008.165. PMC 2439524. PMID 18500378.
- ^ Roch PJ, Henkies D, Carstens JC, Krischek C, Lehmann W, Komrakova M, et al. (2020). "Ostarine and Ligandrol Improve Muscle Tissue in an Ovariectomized Rat Model". Front Endocrinol (Lausanne). 11: 556581. doi:10.3389/fendo.2020.556581. PMC 7528560. PMID 33042018.
- ^ Hoffmann DB, Derout C, Müller-Reiter M, Böker KO, Schilling AF, Roch PJ, et al. (November 2023). "Effects of ligandrol as a selective androgen receptor modulator in a rat model for osteoporosis". J Bone Miner Metab. 41 (6): 741–751. doi:10.1007/s00774-023-01453-8. PMID 37407738. S2CID 259352099.
- ^ a b c d e Dalton JT, Taylor RP, Mohler ML, Steiner MS (December 2013). "Selective androgen receptor modulators for the prevention and treatment of muscle wasting associated with cancer". Curr Opin Support Palliat Care. 7 (4): 345–51. doi:10.1097/SPC.0000000000000015. PMID 24189892. S2CID 35120033.
- ^ a b c Dalton JT, Barnette KG, Bohl CE, Hancock ML, Rodriguez D, Dodson ST, et al. (September 2011). "The selective androgen receptor modulator GTx-024 (enobosarm) improves lean body mass and physical function in healthy elderly men and postmenopausal women: results of a double-blind, placebo-controlled phase II trial". J Cachexia Sarcopenia Muscle. 2 (3): 153–161. doi:10.1007/s13539-011-0034-6. PMC 3177038. PMID 22031847.
- ^ Bhasin S, Jasuja R (May 2009). "Selective androgen receptor modulators as function promoting therapies". Current Opinion in Clinical Nutrition and Metabolic Care. 12 (3): 232–240. doi:10.1097/MCO.0b013e32832a3d79. PMC 2907129. PMID 19357508.
At the doses that have been tested, the first generation SARMs induce modest gains in lean body mass in healthy volunteers, which are nowhere near the much greater gains in skeletal muscle mass reported with supraphysiological doses of testosterone. The modest gains of 1.0 to 1.5 kg in fat-free mass with first generation SARMs over 4–6 weeks should be contrasted with the 5–7 kg gains in fat-free mass with 300 and 600 mg doses of testosterone enanthate. However, it is possible that next generation of SARM molecules will have greater potency and selectivity than the first generation SARMs.
- ^ Bhasin S, Woodhouse L, Casaburi R, Singh AB, Bhasin D, Berman N, et al. (December 2001). "Testosterone dose-response relationships in healthy young men". American Journal of Physiology. Endocrinology and Metabolism. 281 (6): E1172–E1181. doi:10.1152/ajpendo.2001.281.6.E1172. PMID 11701431. S2CID 2344757.
The administration of the GnRH agonist plus graded doses of testosterone resulted in mean nadir testosterone concentrations of 253, 306, 542, 1,345, and 2,370 ng/dl at the 25-, 50-, 125-, 300-, and 600-mg doses, respectively. Fat-free mass increased dose dependently in men receiving 125, 300, or 600 mg of testosterone weekly (change +3.4, 5.2, and 7.9 kg, respectively). The changes in fat-free mass were highly dependent on testosterone dose (P = 0.0001) and correlated with log testosterone concentrations (r = 0.73, P = 0.0001).
- ^ Coss CC, Jones A, Dalton JT (November 2014). "Selective androgen receptor modulators as improved androgen therapy for advanced breast cancer". Steroids. 90: 94–100. doi:10.1016/j.steroids.2014.06.010. PMID 24945109. S2CID 23450056.
- ^ Schmidt A, Kimmel DB, Bai C, Scafonas A, Rutledge S, Vogel RL, et al. (May 2010). "Discovery of the selective androgen receptor modulator MK-0773 using a rational development strategy based on differential transcriptional requirements for androgenic anabolism versus reproductive physiology". J Biol Chem. 285 (22): 17054–64. doi:10.1074/jbc.M109.099002. PMC 2878020. PMID 20356837.
- ^ Wagener F, Guddat S, Görgens C, Angelis YS, Petrou M, Lagojda A, et al. (January 2022). "Investigations into the elimination profiles and metabolite ratios of micro-dosed selective androgen receptor modulator LGD-4033 for doping control purposes". Anal Bioanal Chem. 414 (2): 1151–1162. doi:10.1007/s00216-021-03740-7. PMC 8724150. PMID 34734312.
- ^ Fragkaki AG, Sakellariou P, Kiousi P, Kioukia-Fougia N, Tsivou M, Petrou M, et al. (November 2018). "Human in vivo metabolism study of LGD-4033". Drug Test Anal. 10 (11–12): 1635–1645. doi:10.1002/dta.2512. PMID 30255601. S2CID 263465407.
- ^ Geldof L, Pozo OJ, Lootens L, Morthier W, Van Eenoo P, Deventer K (February 2017). "In vitro metabolism study of a black market product containing SARM LGD-4033". Drug Test Anal. 9 (2): 168–178. doi:10.1002/dta.1930. PMID 26767942.
- ^ Cox HD, Eichner D (January 2017). "Detection of LGD-4033 and its metabolites in athlete urine samples". Drug Test Anal. 9 (1): 127–134. doi:10.1002/dta.1986. PMID 27168428.
- ^ "Ligandrol". PubChem. U.S. National Library of Medicine.
- ^ "Ligandrol". DrugBank.
- ^ a b Hamann LG, Mani NS, Davis RL, Wang XN, Marschke KB, Jones TK (January 1999). "Discovery of a potent, orally active, nonsteroidal androgen receptor agonist: 4-ethyl-1,2,3,4-tetrahydro-6- (trifluoromethyl)-8-pyridono[5,6-g]- quinoline (LG121071)". J Med Chem. 42 (2): 210–2. doi:10.1021/jm9806648. PMID 9925725.
- ^ a b c Gao W, Kim J, Dalton JT (August 2006). "Pharmacokinetics and pharmacodynamics of nonsteroidal androgen receptor ligands". Pharm Res. 23 (8): 1641–58. doi:10.1007/s11095-006-9024-3. PMC 2072875. PMID 16841196.
- ^ Iasuja R, Zacharov MN, Bhasin S (26 July 2012). "The state-of-the-art in the development of selective androgen receptor modulators". Testosterone: action, deficiency, substitution. Cambridge University Press. pp. 459–469. doi:10.1017/cbo9781139003353.022. ISBN 978-1-139-00335-3.
- ^ a b "Viking Therapeutics Initiates Phase 2 Trial of VK5211 in Patients Recovering From Hip Fracture". FierceBiotech. Questex LLC. 21 November 2016.
- ^ Geldof L, Pozo OJ, Lootens L, Morthier W, Van Eenoo P, Deventer K (February 2017). "In vitro metabolism study of a black market product containing SARM LGD-4033". Drug Testing and Analysis. 9 (2): 168–178. doi:10.1002/dta.1930. PMID 26767942.
- ^ Krug O, Thomas A, Walpurgis K, Piper T, Sigmund G, Schänzer W, et al. (November 2014). "Identification of black market products and potential doping agents in Germany 2010-2013". European Journal of Clinical Pharmacology. 70 (11): 1303–1311. doi:10.1007/s00228-014-1743-5. PMID 25168622. S2CID 111542.
- ^ Hahamyan H, Gould H, Gregory A, Dodson C, Gausden E, Voos J, et al. (2023-07-01). "Poster 390: Systematic Review of SARMs Abuse in Athletes". Orthopaedic Journal of Sports Medicine. 11 (7_suppl3): 2325967123S00352. doi:10.1177/2325967123S00352. ISSN 2325-9671. PMC 10392554.
- ^ "WARNING LETTER Panther Sports Nutrition MARCS-CMS 535341 — OCT 23, 2017". FDA. 23 October 2017.
- ^ Cox HD, Eichner D (January 2017). "Detection of LGD-4033 and its metabolites in athlete urine samples". Drug Testing and Analysis. 9 (1): 127–134. doi:10.1002/dta.1986. PMID 27168428.
- ^ Thevis M, Lagojda A, Kuehne D, Thomas A, Dib J, Hansson A, et al. (June 2015). "Characterization of a non-approved selective androgen receptor modulator drug candidate sold via the Internet and identification of in vitro generated phase-I metabolites for human sports drug testing". Rapid Communications in Mass Spectrometry. 29 (11): 991–999. Bibcode:2015RCMS...29..991T. doi:10.1002/rcm.7189. PMID 26044265.
- ^ Hansson A, Knych H, Stanley S, Berndtson E, Jackson L, Bondesson U, et al. (February 2018). "Equine in vivo-derived metabolites of the SARM LGD-4033 and comparison with human and fungal metabolites". Journal of Chromatography. B, Analytical Technologies in the Biomedical and Life Sciences. 1074–1075: 91–98. doi:10.1016/j.jchromb.2017.12.010. PMID 29334634.
- ^ Weislo L (15 March 2024). "Greek track sprinter positive in re-analysis of 2016 Olympics samples". Cyclingnews. Retrieved 18 March 2024.
- ^ Trahan K (12 October 2015). "Florida starting QB Will Grier suspended for at least 2015 after taking banned substance". SB Nation. Retrieved 20 October 2015.
- ^ "NBA bans Joakim Noah 20 games for drug violation". Fox Sports. March 25, 2017. Archived from the original on 26 October 2019.
- ^ Maasdorp J (July 28, 2019). "Shayna Jack reveals banned substance LGD-4033 was behind her doping suspension from swimming". Australian Broadcasting Corporation. Retrieved July 28, 2019.
- ^ "Canada's Vincent Lapointe reveals she tested positive for muscle-building substance". CBC. 20 August 2019.
- ^ "Dopage : Laurence Vincent Lapointe blanchie et soulagée" [Doping: Laurence Vincent Lapointe cleared and relieved]. Radio Canada (in French). 27 January 2020.
- ^ Briggs S (15 January 2020). "Wimbledon doubles champion Robert Farah fails drugs test". Telegraph Media Group Limited.
- ^ "Commonwealth gold medallist Nwokocha provisionally suspended for doping". Reuters. 2022-09-03. Retrieved 2023-05-09.
- ^ "Cavs' Tristan Thompson suspended 25 games without pay by NBA". National Basketball Association. January 23, 2024. Retrieved January 23, 2024.
- ^ Heroux D. "Curler Briane Harris faces 4-year suspension after testing positive for banned substance, plans to appeal". CBC Sports. Retrieved 12 March 2024.
- ^ Bautz D (21 November 2016). "VKTX: Additional Preclinical Data Shows Robust and Durable Weight Gain for VK5211-Treated Primates". Yahoo. Yahoo, Inc.