ACP-105 is a nonsteroidal SARM that Acadia Pharmaceuticals described in 2009 as a partial activator of the androgen receptor. In a 2-week study in castrated rats it improved anabolic measures, and in mouse studies it reduced anxiety-like behavior (Schlienger 2009; George 2013). It has never been tested as a treatment in people (ClinicalTrials.gov), and its human safety is unknown: a 2025 paper could only predict its toxicity with computer models (Fijałkowska 2025). It is not approved anywhere, and anti-doping agencies treat it as a banned SARM (UK Anti-Doping).
Below: what ACP-105 is and how it works, every study, its claimed benefits against the evidence, dosage, cycle length and half-life, side effects, legal status, and how it compares with AC-262 and ostarine.
What is ACP-105?
ACP-105 (also written ACP105) is a nonsteroidal selective androgen receptor modulator discovered at Acadia Pharmaceuticals’ Malmö site and published in 2009 (Schlienger 2009; PubChem CID 11638442). It comes from the same company as AC-262 (accadrine). We found no record of clinical development; later work is in mice and in anti-doping laboratories (ClinicalTrials.gov).
How does ACP-105 work?
It binds the androgen receptor, the receptor testosterone uses, but in cell tests it only partly activated it compared with testosterone, which makes it a partial agonist (Schlienger 2009). How that plays out in people has never been measured.
ACP-105 research at a glance
| Study | Model | What it found | Evidence |
|---|---|---|---|
| Schlienger 2009 | Cells; castrated rats, 2 weeks | Partial agonist; improved anabolic parameters. | Cell, animal |
| Dayger 2011 | Female mice after irradiation | Prevented the radiation-related drop in rotorod (balance and coordination) performance; enhanced cued fear conditioning. | Animal |
| George 2013 | Gonadectomized Alzheimer’s-model mice | ACP-105 alone reduced anxiety-like behavior. With an estrogen-receptor-beta drug (AC-186) it lowered amyloid-beta and improved memory. | Animal |
| Thevis 2013, 2014 (Thevis 2013; Thevis 2014) | Rats | Breakdown products detectable for up to 4 and 6 days. | Anti-doping study |
| Broberg 2023 | One person, single 100 µg dose | Seven breakdown products in urine; two suggested as testing targets. | Anti-doping study |
| Fijałkowska 2025 (Fijałkowska 2025; Fijałkowska 2025) | Computer models | Predicted toxicity and ADME, including a predicted half-life of about 1.2 hours. Predictions, not measurements. | In silico |
Compare ACP-105 with other compounds in the SARMs database.
ACP-105 benefits: claims vs evidence
- Muscle: improved anabolic parameters in a 2-week study in castrated rats (Schlienger 2009). Not tested in people.
- Anxiety and mood: reduced anxiety-like behavior in an Alzheimer’s mouse model (George 2013). Not tested in people.
- Memory and Alzheimer’s: improved memory and lower amyloid-beta only when combined with a second drug, AC-186, in mice (George 2013).
- Coordination after radiation: protected rotorod performance in irradiated female mice (Dayger 2011).
- Fat loss and strength: no study in any model.
ACP-105 results and before-and-after reports
There are no measured human results. Photos and reviews cannot separate ACP-105’s effect from training, diet, other compounds or a mislabeled product. For what SARMs with human trials actually achieved, roughly 1 to 1.5 kg of lean mass, see SARMs before and after (Adolf 2026).
ACP-105 dosage, cycle length and half-life
No treatment dose or cycle length has been studied in people. The only human dose on record is a single 100 µg dose in an anti-doping study that looked at breakdown products, not effects (Broberg 2023). Rat and mouse doses do not translate to people. Its half-life has not been measured in people or animals; a 2025 computer-model study predicted about 1.2 hours, which is a prediction, not a measurement (Fijałkowska 2025). Doses and cycle lengths seen online come from user reports, not studies. See best time to take SARMs for what is known about timing in general.
ACP-105 side effects
Unknown in people: there is no safety study and we found no case report naming it (ClinicalTrials.gov). What exists:
- Predicted toxicity only. With no toxicity studies to draw on, a 2025 paper used computer models to predict its toxicity, including organ effects, genotoxicity and heart (hERG) effects (Fijałkowska 2025). A second 2025 modeling paper predicted possible DNA and protein interactions and cyanide release (Fijałkowska 2025). These are untested predictions.
- Harms linked to SARM products. The FDA says life-threatening reactions, including liver injuries needing hospital care, have occurred in people taking SARM products, and lists possible risks including heart attack or stroke, liver failure and infertility (FDA).
- Mislabeled products. In a test of 44 products sold online as SARMs, only 52% contained a SARM and 41% matched the label (Van Wagoner 2017).
Across SARMs: SARMs side effects and are SARMs liver toxic?
Does ACP-105 suppress testosterone? Does it need PCT?
Not known. We found no study that measured testosterone, LH or FSH with ACP-105 (Schlienger 2009). Its sister compound AC-262 lowered LH in castrated rats (Piu 2008), but that has not been tested for ACP-105. What is known about hormone recovery after SARMs and the PCT drugs that have been studied: PCT after SARMs, the PCT and bloodwork planner and the SARMs bloodwork guide.
Is ACP-105 legal?
- United States: not FDA-approved. ACP-105 is not named in the FDA notices we found, but the FDA says products sold as SARMs are unapproved drugs, not dietary supplements (FDA).
- United Kingdom: UK Anti-Doping lists ACP-105 among commonly available SARMs, says no SARM is approved for human use, and notes that SARMs are illegal to sell or advertise as food or in supplements (UK Anti-Doping).
- Australia: not named, but SARMs as a class are prescription-only and possession without authority is illegal (Poisons Standard 2026).
More: are SARMs legal?
ACP-105 in sport and drug tests
It is not named on WADA’s 2026 List, but S1.2 bans SARMs as a class (WADA 2026), and UK Anti-Doping lists ACP-105 as prohibited (UK Anti-Doping). Validated methods detect it in human urine and hair (Stacchini 2021; Gheddar 2021), and two of its hydroxylated breakdown products have been proposed as testing targets (Broberg 2023). See SARMs drug test.
ACP-105 vs AC-262 and ostarine
| Compound | Evidence | Human data |
|---|---|---|
| ACP-105 | 2-week castrated rat study; mouse anxiety, memory and radiation studies | None as a treatment |
| AC-262 | 2-week castrated rat study (Piu 2008) | None |
| Ostarine | Phase 2 and Phase 3 human trials | +1.3 kg lean mass vs placebo on 3 mg/day; lower HDL and total testosterone (Dalton 2011) |
Compare them side by side with the compare tool.
Buying ACP-105: what to check
With no human data and frequent mislabeling across SARM products (Van Wagoner 2017), a lot-specific certificate of analysis is the only check on what is in the bottle. Learn how to read a lab test, and see where to buy SARMs for what to check with any seller.
Bottom line
ACP-105 is a partial-agonist SARM with a 2-week rat study and a few mouse studies behind it, mostly about anxiety, memory and coordination rather than muscle. It has never been tested as a treatment in people, its half-life and hormone effects are unknown, and its toxicity has only been predicted by computer models. It is banned in sport and cannot legally be sold as a supplement in the US or UK.
Charts
Source: Sarmguide compound database; ACP-105 value: First multifaceted ADME profile of ACP-105 (CAS: 1048998-11-3): a novel non-steroidal selective androgen receptor modulator used as doping in sports-integrative in silico toxicological studies for clinical and forensic toxicology purposes (2025).
Frequently asked questions
What is ACP-105?
An untested partial-agonist SARMEvidence: Animal
ACP-105 is a nonsteroidal SARM described by Acadia Pharmaceuticals in 2009. It has been tested in rats and mice, not in people.
How does ACP-105 work?
Partial androgen-receptor agonistEvidence: Lab
It binds the androgen receptor but in cell tests only partly activated it compared with testosterone. How that plays out in people has never been measured.
What are the benefits of ACP-105?
None shown in peopleEvidence: Animal
In castrated rats it improved anabolic measures over 2 weeks, and in mice it reduced anxiety-like behavior and protected coordination after radiation. Fat loss and strength have not been studied in any model.
What is the dosage of ACP-105?
No human dose studiedEvidence: Limited
No treatment dose has been studied in people; the only human dose on record is a single 100 µg dose in an anti-doping study of its breakdown products. Rat and mouse doses do not translate to people.
What is the half-life of ACP-105?
Not measuredEvidence: Limited
A 2025 computer-model study predicted about 1.2 hours, but no study in animals or people has measured it.
Has ACP-105 been tested in humans?
Not as a treatmentEvidence: Limited
ClinicalTrials.gov lists no trials. The only human data come from an anti-doping study of a single 100 µg dose that looked at its breakdown products.
What are the side effects of ACP-105?
Unknown in peopleEvidence: Limited
There is no safety study or case report; a 2025 paper could only predict its toxicity with computer models. The FDA warns that SARM products have caused liver injuries needing hospital care.
Does ACP-105 suppress testosterone?
UnknownEvidence: Limited
No study has measured testosterone, LH or FSH with ACP-105. Its sister compound AC-262 lowered LH in castrated rats.
ACP-105 vs ostarine: what is the difference?
Ostarine has human trialsEvidence: Trial
Ostarine has been tested in human trials up to Phase 3; ACP-105 has only rat and mouse data. Both are nonsteroidal SARMs, and WADA bans both.
ACP-105 vs AC-262: what is the difference?
Sister SARMs, both untestedEvidence: Animal
Both are nonsteroidal partial-agonist SARMs from Acadia Pharmaceuticals, published in 2009 and 2008. Neither has been tested in people; ACP-105 also has mouse studies.
Is ACP-105 legal, and is it banned in sport?
Not approved; banned in sportEvidence: Law
It is not approved anywhere and cannot legally be sold as a supplement in the US or UK. WADA bans SARMs as a class under S1.2, and UK Anti-Doping lists ACP-105 as prohibited.
Sources
- Synthesis, structure-activity relationships, and characterization of novel nonsteroidal and selective androgen receptor modulators
- Nonsteroidal selective androgen receptor modulators and selective estrogen receptor β agonists moderate cognitive deficits and amyloid-β levels in a mouse model of Alzheimer's disease
- ClinicalTrials.gov search for 'ACP-105' and 'ACP105': no studies found (checked 30 October 2026)
- Toxicity of ACP-105: a substance used as doping in sports: application of in silico methods for prediction of selected toxicological endpoints
- SARMs | UK Anti-Doping (supplement ingredient warning, updated 29 April 2026)
- PubChem: ACP-105 (CID 11638442), names and synonyms
- Expanding sports drug testing assays: mass spectrometric characterization of the selective androgen receptor modulator drug candidates RAD140 and ACP-105
- Liquid chromatography-high resolution/ high accuracy (tandem) mass spectrometry-based identification of in vivo generated metabolites of the selective androgen receptor modulator ACP-105 for doping control purposes
- First multifaceted ADME profile of ACP-105 (CAS: 1048998-11-3): a novel non-steroidal selective androgen receptor modulator used as doping in sports-integrative in silico toxicological studies for clinical and forensic toxicology purposes
- Effects of the SARM ACP-105 on rotorod performance and cued fear conditioning in sham-irradiated and irradiated female mice
- Selective Androgen Receptor Modulators (SARMs) in Sport: Patterns of Use, Product Contamination, Health Risks and Doping-Control Implications
- A multivariate data analysis approach for the investigation of in vitro derived metabolites of ACP-105 in comparison with human in vivo metabolites
- 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
- Pharmacological characterization of AC-262536, a novel selective androgen receptor modulator
- Therapeutic Goods (Poisons Standard—June 2026) Instrument 2026 (F2026L00633)
- WADA: The Prohibited List (2026 List, in force from 1 January 2026)
- Simultaneous detection of different chemical classes of selective androgen receptor modulators in urine by liquid chromatography-mass spectrometry-based techniques
- Development and validation of SARMs and metabolic modulators screening in hair using UHPLC-MS/MS: Application to a doping case and first identification of S23 in authentic human hair
- 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