Andarine (S4, GTx-007) was one of the first SARMs. Ohio State and GTx researchers studied it in rats and dogs from 2004 to 2009, where it restored muscle and bone with little effect on the prostate (Gao 2005). A 2024 review says its development stopped before human trials, and ClinicalTrials.gov lists none (Leciejewska 2024; ClinicalTrials.gov). Human reports are limited to case reports and FDA adverse event reports, usually with other drugs involved. It is not approved anywhere, and WADA bans it (WADA 2026).
Below: what andarine is, every study we found, its effects and side effects (including the vision claim), the half-life and dosage question, its legal status, and links to all of our andarine guides.
What is andarine (S4)?
Andarine is a nonsteroidal aryl-propionamide SARM, from the same family as ostarine and S-23. Its other names are S-4, S4, GTx-007, acetamidoxolutamide and androxolutamide (PubChem CID 9824562; UK Anti-Doping). GTx took a related compound from the same family, ostarine (enobosarm), into human trials; andarine itself stopped at the animal stage (Leciejewska 2024).
A 2024 review notes that andarine’s structure includes an aromatic nitro group, a feature linked to toxicity in drug design, and suggests it may be more toxic than related SARMs; that has not been tested (Leciejewska 2024).
Andarine research at a glance
| Study | Model | What it found | Evidence |
|---|---|---|---|
| Kearbey 2004 | Rats | Half-life 2.6–5.3 hours; oral absorption depended on dose. | Animal |
| Gao 2005 | Castrated rats, 3 or 10 mg/kg for 8 weeks | Soleus muscle mass and strength and levator ani mass restored to intact levels. Prostate and seminal vesicles reached only 16% and 17% of intact weight at 3 mg/kg, while DHT more than doubled them. Bone density rose more than with DHT. LH and FSH fell with dose. | Animal |
| Perera 2006 | Dogs | Half-life about 200 minutes; 91% oral bioavailability. | Animal |
| Kearbey 2007 | Female rats after ovary removal, 120 days | Bone density and strength kept; body fat fell. | Animal |
| Kearbey 2009 | Osteopenic female rats | Bone density restored. | Animal |
| Sotorník 2022 | A 47-year-old bodybuilder using RAD-140, andarine and ibutamoren | Blood sugar 558 mg/dL; needed insulin; HbA1c normal within a year of stopping. | Case report |
No study has tested andarine in people for any outcome (ClinicalTrials.gov). Compare it with other compounds in the SARMs database.
Andarine benefits: what the evidence shows
Muscle and strength
In castrated rats, 8 weeks of andarine restored muscle mass and strength to normal levels (Gao 2005). That is a model of testosterone deficiency, not of a healthy person training. No human study exists.
Fat loss and recomposition
Body fat fell in treated female rats (Kearbey 2007). Andarine’s reputation as a cutting and recomposition SARM rests on that and on user reports; no human data exist.
Bone
This is where the rat data are strongest: bone density rose more than with DHT in castrated rats, bone was protected after ovary removal, and bone density was restored in osteopenic female rats (Gao 2005; Kearbey 2007; Kearbey 2009).
Andarine results and before-and-after reports
There are no measured human results. User reports and photos are on S4 (andarine) before and after, and our older andarine review with user results has more. Photos cannot separate andarine’s effect from training, diet, other drugs or a mislabeled product.
Andarine side effects
| Side effect | What was found | Evidence |
|---|---|---|
| Very high blood sugar (with RAD-140 and ibutamoren) | Blood sugar 558 mg/dL, heavy thirst, 10 kg weight loss and blurred vision after 3 months; insulin needed. He already had fatty liver and impaired fasting glucose, and the authors think ibutamoren played the main role (Sotorník 2022). | Case report |
| FDA adverse event reports | Three reports name andarine: dizziness and near-fainting (27-year-old man, 2017), acute liver failure (26-year-old man, 2018; matching reports name the same brand’s ostarine and ligandrol) and a cardiac death (2019) (Leciejewska 2024). | Adverse event reports |
| Hidden in a supplement | FDA lab tests found andarine and ostarine in a product sold as a dietary supplement, which was recalled; FDA said SARMs may cause acute liver injury (FDA 2017). | Regulator warning |
| Chemical warning sign | An aromatic nitro group, linked to toxicity in drug design (Leciejewska 2024). | Theoretical |
| Harms linked to SARM products | Life-threatening reactions including liver injuries needing hospital care; possible risks include heart attack or stroke, liver failure and infertility (FDA). | Regulator warning |
| Mislabeled products | Andarine was one of three SARMs found when 44 products sold online as SARMs were tested; only 41% matched the label (Van Wagoner 2017). | Lab analysis |
Adverse event reports and single cases cannot prove that andarine caused a problem, but they are the only human safety data there are. Across SARMs: SARMs side effects, liver, hair loss and gyno.
Andarine and vision: yellow tint and night vision
The best-known andarine side effect online is a yellow tint to vision and trouble seeing in the dark. We searched PubMed for andarine and SARMs together with vision, visual, retina and eye, and found no study or case report describing it. So it is not established: it may be a real effect that has never been studied, or a claim repeated without a source. The only vision symptom in a published andarine case was blurred vision, which came together with very high blood sugar in a man also taking RAD-140 and ibutamoren (Sotorník 2022).
Does andarine suppress testosterone?
In castrated rats, andarine lowered LH and FSH in a dose-dependent way (Gao 2005). No trial has measured it in men. In the one detailed human case, a man taking andarine with RAD-140 and ibutamoren had low SHBG, total testosterone and estradiol while free testosterone, LH and FSH were normal; all returned to normal after he stopped (Sotorník 2022).
Source: Sarmguide compound database; Andarine (S4): Selective androgen receptor modulator treatment improves muscle strength and body composition and prevents bone loss in orchidectomized rats (2005).
More: PCT after SARMs, do SARMs lower testosterone? and the PCT and bloodwork planner.
Bloodwork
No trial has tracked lab markers. Glucose, HbA1c, SHBG and total testosterone changed in the one detailed case report (with other drugs), and LH and FSH fell in rats:
- Fasting glucose and HbA1c
- ALT and AST (liver enzymes)
- SHBG, total and free testosterone, LH and FSH
How to read them: SARMs bloodwork guide.
Andarine dosage: what studies used
No human dose has been studied. The rat studies used doses per kilogram of body weight (for example 3 or 10 mg/kg), and those do not translate to people (Gao 2005). Products are sold by label strength; SwissChems, for example, sells andarine as 25 mg capsules. Our S4 dosage page explains what users report and what is known.
Andarine half-life and when to take it
Not measured in people. In rats the half-life was 2.6–5.3 hours (Kearbey 2004) and in dogs about 3.3 hours (Perera 2006), shorter than the 14–24 hours measured for ostarine in people (EMERALD protocol 2021). Whether a short animal half-life means split dosing makes sense in people has never been tested. See best time to take SARMs.
Is andarine legal?
- United States: not FDA-approved. December 2025 FDA warning letters called products sold as “S-4” (andarine) and “S4 Andarine” unapproved new drugs (FDA warning letter, 2025; FDA warning letter, 2025), and in 2017 a dietary supplement was recalled after FDA found andarine and ostarine in it (FDA 2017).
- United Kingdom: UK Anti-Doping lists andarine (GTx-007, S-4) among SARMs; no SARM is approved for human use, and SARMs are illegal to sell or advertise as food or in supplements (UK Anti-Doping).
- Australia: SARMs as a class are prescription-only, and possession without authority is illegal (Poisons Standard 2026).
- Germany: named as “Andarin (S-4)” in the Anti-Doping Act’s annex (AntiDopG annex); trading in it for doping in sport, or possessing a non-small quantity for that purpose, is banned (AntiDopG §2).
- Prescription: because andarine is not an approved medicine anywhere, there is no prescription version, in the Netherlands or elsewhere.
More: are SARMs legal? and SARMs in Europe.
Andarine in sport and drug tests
WADA names andarine on its Prohibited List, banned at all times (WADA 2026). The Swiss anti-doping laboratory reported the first case of SARM abuse found in in-competition testing in 2010, and it involved S-4 (Grata 2011). WADA recorded 1 to 3 andarine findings a year from 2015 to 2020 (Leciejewska 2024). See SARMs drug test.
Andarine vs ostarine and other SARMs
| Compound | Human evidence | What is known |
|---|---|---|
| Andarine (S4) | None | Restored muscle and bone in castrated rats with little prostate effect (Gao 2005) |
| Ostarine | Phase 2 and Phase 3 trials | +1.3 kg lean mass vs placebo on 3 mg/day for 86 days; lower HDL and total testosterone (Dalton 2011) |
| S-23 | None | Full androgen in rats; studied as a male contraceptive (Jones 2009) |
| Cardarine (not a SARM) | Short lipid trials | Cancers in 2-year animal studies (Toxicologist 2009) |
Head-to-head: andarine vs ostarine, or the compare tool.
Andarine stacks
No study has tested andarine with anything. The detailed human cases involve combinations: diabetes-level blood sugar with RAD-140 and ibutamoren (Sotorník 2022), and severe liver injury in a 2026 RAD-140 case where the product also contained andarine (Dao 2026). Check overlapping risks with the stack checker.
Buying andarine: is it what the label says?
Andarine has turned up undeclared in supplements (FDA 2017), and in a test of 44 products sold as SARMs only 41% matched their label amount (Van Wagoner 2017). Look for a lot-specific certificate of analysis and learn how to read a lab test. Our current pick is SwissChems, which publishes lot-specific lab reports; see our SwissChems review.
Bottom line
Andarine is an early SARM whose results in rats were good, especially for bone, and whose development stopped before any human trial. Everything said about its effects in people comes from user reports. The human safety record is a diabetes-level blood sugar case with other drugs and a handful of FDA adverse event reports, and the famous vision side effect has never been documented in published research. It is banned in sport and cannot legally be sold as a supplement in the US or UK.
Charts
Source: Sarmguide compound database; Andarine (S4) value: Pharmacokinetics of S-3-(4-acetylamino-phenoxy)-2-hydroxy-2-methyl-N-(4-nitro- 3-trifluoromethyl-phenyl)-propionamide in rats, a non-steroidal selective androgen receptor modulator (2004).
More on Andarine (S4)
Frequently asked questions
What is andarine (S4)?
An early, untested SARMEvidence: Animal
Andarine (S4, GTx-007) is a nonsteroidal SARM that, in rats, restored muscle and bone with much less effect on the prostate than DHT. It never reached human trials.
What are the benefits of andarine?
Shown in rats onlyEvidence: Animal
Castrated rats regained normal muscle mass and strength, bone density rose more than with DHT, and female rats lost body fat. No benefit has been measured in people.
What do andarine before and after results show?
No measured human resultsEvidence: User reports
Online photos cannot separate andarine's effect from training, diet, other drugs or a mislabeled product. In a 2017 test of 44 products sold as SARMs, only 41% matched the label.
Has andarine been tested in humans?
NoEvidence: Limited
A 2024 review says its development stopped before human trials, and ClinicalTrials.gov lists none.
What side effects has andarine been linked to?
Case reports, other drugs involvedEvidence: Human data
One man on andarine, RAD-140 and ibutamoren developed diabetes-level blood sugar. FDA adverse event reports name andarine for dizziness, liver failure and one cardiac death, which do not prove cause.
Does andarine affect vision?
Not establishedEvidence: User reports
The yellow tint and poor night vision described online have no published study or case report behind them. The only published vision symptom was blurred vision with very high blood sugar, in a man also taking other drugs.
Does andarine suppress testosterone?
In rats; unknown in menEvidence: Animal
In castrated rats it lowered LH and FSH, and no trial has measured it in men. In one case report, a man using it with other drugs had low SHBG and total testosterone that recovered after stopping.
What is the half-life of andarine?
Not measured in peopleEvidence: Animal
In rats it was 2.6–5.3 hours, and in dogs about 3.3 hours.
When should you take andarine?
Never studiedEvidence: Limited
No study has tested dosing times in people. Its half-life is short in rats and dogs, but whether that applies to people has never been measured.
What dose of andarine was used in studies?
No human dose studiedEvidence: Animal
Rat studies used doses per kilogram of body weight, such as 3 or 10 mg/kg, and those do not translate to people.
Is andarine legal?
Not approved anywhereEvidence: Law
The FDA calls products sold as S4 or andarine unapproved new drugs. In the UK, SARMs cannot legally be sold as supplements, and in Australia possession without authority is illegal.
Is andarine banned in sport?
Yes, banned by WADAEvidence: Law
WADA names andarine on its Prohibited List, banned at all times. The Swiss anti-doping lab's first reported in-competition SARM case, in 2010, involved S-4.
Sources
- Selective androgen receptor modulator treatment improves muscle strength and body composition and prevents bone loss in orchidectomized rats
- Selective androgen receptor modulator use and related adverse events including drug-induced liver injury: Analysis of suspected cases
- ClinicalTrials.gov search for 'andarine' and 'GTx-007': no studies found (checked 30 October 2026)
- WADA: The Prohibited List (2026 List, in force from 1 January 2026)
- PubChem: Andarine (CID 9824562), names and synonyms
- SARMs | UK Anti-Doping (supplement ingredient warning, updated 29 April 2026)
- Selective Androgen Receptor Modulator (SARM) treatment prevents bone loss and reduces body fat in ovariectomized rats
- Effects of selective androgen receptor modulator (SARM) treatment in osteopenic female rats
- Could Overt Diabetes Be Triggered by Abuse of Selective Androgen Receptor Modulators and Growth Hormone Secretagogues? A Case Report and Review of the Literature
- FDA recall notice: Tri-Ton dietary supplement recalled due to the presence of andarine and ostarine (company announcement 19 May 2017)
- FDA: Certain bodybuilding products put consumers at risk for heart attack, stroke, serious liver damage and more (content current as of 2 December 2025)
- Chemical Composition and Labeling of Substances Marketed as Selective Androgen Receptor Modulators and Sold via the Internet
- Pharmacokinetics of S-3-(4-acetylamino-phenoxy)-2-hydroxy-2-methyl-N-(4-nitro- 3-trifluoromethyl-phenyl)-propionamide in rats, a non-steroidal selective androgen receptor modulator
- In vivo metabolism and final disposition of a novel nonsteroidal androgen in rats and dogs
- EMERALD study protocol (ISRCTN12213700, University of Liverpool, version 6.0, 2021): a window of opportunity study of enobosarm in ER+/AR+ early breast cancer
- FDA Warning Letter to an online seller of products marketed as SARMs (MARCS-CMS 719645), 12 December 2025
- FDA Warning Letter to an online seller of products marketed as SARMs (MARCS-CMS 719337), 12 December 2025
- Therapeutic Goods (Poisons Standard—June 2026) Instrument 2026 (F2026L00633)
- Anlage zum Anti-Doping-Gesetz (AntiDopG), Germany (BGBl. 2023 I Nr. 67)
- § 2 Anti-Doping-Gesetz (AntiDopG): Unerlaubter Umgang mit Dopingmitteln (Germany)
- SARM-S4 and metabolites detection in sports drug testing: a case report
- 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
- Preclinical characterization of a (S)-N-(4-cyano-3-trifluoromethyl-phenyl)-3-(3-fluoro, 4-chlorophenoxy)-2-hydroxy-2-methyl-propanamide: a selective androgen receptor modulator for hormonal male contraception
- Rat carcinogenicity study with GW501516, a PPAR delta agonist (Geiger et al., The Toxicologist 2009, abstract 895)
- Unregulated gains: a case of RAD-140-induced liver injury
