ACP-105 Review: What the Research Actually Shows

Key takeaways

What Is ACP-105?

ACP-105 is a non-steroidal selective androgen receptor modulator (SARM), chemically classified as an aniline-type compound with the CAS number 1048998-11-3. It is structurally related to two other investigational SARMs, AC-262536 and vosilasarm (RAD140), and its regulatory status in the United States is listed as an investigational new drug, meaning it has never been reviewed or approved by the Food and Drug Administration for any indication.

The compound was discovered by ACADIA Pharmaceuticals through a high-throughput screen using receptor selection and amplification technology, and was nominated as a formal development candidate in February 2006. ACADIA described ACP-105 at the time as a molecule that selectively activates the androgen receptor and belongs to the SARM class, which the company suggested could eventually offer an alternative to testosterone-based treatments for muscle-wasting conditions and osteoporosis with improved tolerability. The company stated its intention to conduct toxicology and other testing in preparation for potential clinical trials.

Two years later, ACADIA presented additional preclinical findings at the Experimental Biology 2008 meeting, describing ACP-105 as being as potent and efficacious as testosterone in in vitro assays without interaction at other hormone receptors, and reporting anabolic effects on muscle and bone with minimal effect on the prostate in preclinical models. Public disclosures from ACADIA about ACP-105 end at this point. No later company statement, regulatory filing, or peer-reviewed clinical report describing human testing of ACP-105 by ACADIA has been identified, and the compound does not appear to have advanced further in that company's pipeline.

Pharmacology in Castrated Rats

The most substantive primary data on ACP-105 come from a 2009 peer-reviewed medicinal chemistry paper describing the discovery and structure-activity relationships of a series of nonsteroidal SARMs, including ACP-105. That paper reported that in a two-week chronic study in castrated male rats, ACP-105 improved anabolic parameters. This is standard early pharmacological screening data used to characterize candidate SARMs in animal models, and it is several steps removed from evidence of efficacy or safety in humans.

Separately, ACADIA's own conference disclosures described ACP-105 as producing potent anabolic effects on muscle and bone with minimal effect on the prostate in preclinical models, consistent with the general tissue-selectivity goal of the SARM class. These findings have not been independently replicated in an academic, non-industry publication, and no chronic dosing study beyond two weeks in rodents has been identified in the published literature.

Cognitive and Neuroprotective Findings in Mice

A separate line of research, conducted by investigators at Oregon Health and Science University, examined ACP-105 in the context of radiation-induced cognitive decline. In a 2011 study published in Brain Research, female C57BL/6J mice were sham-irradiated or irradiated with cesium-137 and treated with ACP-105 or vehicle, then tested on rotorod motor performance and fear conditioning. Irradiation impaired sensorimotor function in vehicle-treated mice but not in ACP-105-treated mice, and irradiation impaired cued fear conditioning while ACP-105 enhanced fear conditioning in both sham-irradiated and irradiated mice. Effects on a brain protein marker (MAP-2) differed by cortical region, with reduced immunoreactivity in the sensorimotor cortex and a trend toward increased immunoreactivity in the entorhinal cortex.

A second, related study published in ACS Chemical Neuroscience in 2013 examined nonsteroidal SARMs and selective estrogen receptor beta agonists, including ACP-105, in a mouse model of Alzheimer's disease, reporting effects on cognitive deficits and amyloid-beta levels. Both studies came from an overlapping group of investigators with a specific research interest in androgen and estrogen receptor beta signaling in the brain, using aged, irradiated, or transgenic female mouse models. This is a legitimate but narrow experimental niche rather than a broad or independently replicated evidence base, and no human cognitive or neuroprotective trial of ACP-105 has followed either study.

Detection in Doping Control: Horses and Humans

Despite the absence of any published human clinical trial, ACP-105 has moved into real-world human use outside of medical supervision. A 2025 in silico toxicology paper describes ACP-105 as a SARM that is increasingly detected in anti-doping analyses, which indicates that people are taking the compound even though it has never been tested for safety or efficacy in a controlled human study. This detection-versus-testing gap is an important distinction: being found in urine or blood samples during doping control reflects unsupervised human exposure, not clinical evidence of safety.

Anti-doping laboratories have also worked to characterize how ACP-105 is broken down in the body of other species so that its use can be detected. Researchers have identified in vitro metabolites of ACP-105 and six other nonsteroidal SARMs in horses for doping control purposes, published in the journal Drug Testing and Analysis. Work of this kind is aimed at building analytical methods to catch doping, not at establishing therapeutic safety or efficacy, and it does not substitute for controlled pharmacokinetic or toxicology studies in the target species of interest, including humans.

The 2025 Computational Safety Modeling

The most recent published work on ACP-105, from 2025, is entirely computational. Researchers generated the first integrative in silico characterization of ACP-105's absorption, distribution, metabolism, and excretion (ADME) properties using seven independent prediction methods, explicitly because a comprehensive ADME profile did not otherwise exist. The models estimated high gastrointestinal absorption, moderate lipophilicity, low aqueous solubility, and a range of predicted Caco-2 permeability values.

The authors were explicit that this work was necessary because toxicological data on SARMs including ACP-105 are very limited, and that what is known comes almost exclusively from experimental studies in animals and in vitro models rather than from humans. In silico modeling of this kind can flag plausible metabolic pathways and rough exposure parameters, but it is a prediction tool, not a substitute for measured pharmacokinetics or controlled human safety data.

How Strong Is the Evidence, Overall?

Grading the strength of evidence for ACP-105 is straightforward because there is so little of it. The pharmacological characterization of its anabolic effects in castrated rats rests on one peer-reviewed medicinal chemistry paper from 2009 and a small number of industry conference disclosures from ACADIA Pharmaceuticals dating from 2006 and 2008. This is standard early-stage SARM discovery data, useful for screening candidate molecules, but several steps removed from evidence of efficacy or safety in humans.

The cognitive and neuroprotective findings in irradiated and Alzheimer's-model mice come from a small number of studies by an overlapping group of investigators interested in androgen and estrogen receptor beta signaling in the brain. These are legitimate peer-reviewed publications, but they represent a narrow experimental niche (irradiated or transgenic female mice) rather than a broad or replicated evidence base, and no human cognitive or neuroprotective trial has followed.

The most recent literature, from 2025, is entirely computational: in silico predictions of absorption, distribution, metabolism, and excretion, generated explicitly because real toxicological data in animals or humans is lacking. The authors were direct in stating that toxicological knowledge of SARMs like ACP-105 remains very limited and comes almost exclusively from animal and in vitro work. In silico modeling can flag plausible metabolic pathways and rough exposure parameters, but it cannot substitute for measured pharmacokinetics, let alone controlled safety data.

Taken together, the evidence for ACP-105 sits at the earliest end of the drug development spectrum: in vitro receptor assays, single-species rodent pharmacology, a couple of mouse cognition studies, a doping-detection metabolite study in horses, and computer-generated safety predictions. There is no published human pharmacokinetic study, no published human safety study, and no published human efficacy study of any kind. Claims found on commercial or bodybuilding-oriented websites describing specific human benefits, fat-loss outcomes, dosing protocols, or side-effect rates for ACP-105 are not supported by any citation to human research in the published literature reviewed here.

Regulatory and Legal Status

No SARM, including ACP-105, is approved by the FDA for any use in the United States. The FDA has stated that although SARMs are often marketed as dietary supplements or sold as 'research chemicals,' they are unapproved drugs, and the agency has warned that products containing SARMs have been linked to life-threatening reactions including liver injuries requiring hospitalization. The FDA has issued numerous warning letters to companies selling SARM products and has pursued enforcement action against manufacturers and distributors.

SARMs as a class, including unnamed or newer compounds such as ACP-105, are prohibited at all times, both in and out of competition, under the World Anti-Doping Agency's Prohibited List, where they are listed as Other Anabolic Agents. This blanket prohibition applies regardless of whether a specific SARM is individually named on the list, which is why anti-doping laboratories continue to develop detection methods for compounds like ACP-105 even though it is not one of the handful of SARMs most commonly named by name.

Reported Risks and Safety Concerns

Because no controlled human study of ACP-105 has been published, there is no reliable human safety data specific to this compound. Statements about its side effects in humans, including claims about liver enzymes, lipid changes, or testosterone suppression that circulate on bodybuilding and research-chemical retail sites, are not derived from clinical trials and should not be treated as established facts about ACP-105 itself.

What can be said comes from the SARM class as a whole. Regulatory and clinical sources describe SARMs generally as being associated with risks including liver injury, adverse cardiovascular events, and unfavorable changes in cholesterol and lipid profiles, based on the limited human exposure that has occurred through unsupervised use and the handful of other SARMs that have reached human trials. Athletes and other users have also been reported to take SARMs at doses well above anything studied in animals, which may further increase risk. None of this constitutes direct evidence about ACP-105's safety profile in humans, but it illustrates why regulators treat the entire class with caution even when a specific compound like ACP-105 has almost no dedicated human data at all.

Bottom Line

ACP-105 is a real, chemically characterized SARM with a documented discovery history at ACADIA Pharmaceuticals and a small but legitimate body of preclinical pharmacology and neuroscience research. That research shows anabolic effects in castrated rats and cognitive effects in specific mouse models of radiation exposure and Alzheimer's disease. It does not show that ACP-105 is safe or effective in humans, because no such study has ever been published. The compound is not approved by the FDA for any purpose, is not a legal dietary supplement, and is prohibited in all forms of drug-tested competitive sport. Anyone encountering marketing claims about ACP-105's benefits or dosing should recognize that these claims extrapolate from rodent data and internet forum reports rather than from clinical evidence.

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