ACP-105: How Is It Taken? What the Research Actually Shows

Key takeaways

Why There Is No Legitimate Answer to "How to Take ACP-105"

Searches for administration instructions typically assume a compound has an established, tested human dose. That assumption does not hold for ACP-105. The compound is a non-steroidal selective androgen receptor agonist that emerged from a drug discovery program at ACADIA Pharmaceuticals. The company nominated it as a development candidate in February 2006, describing it as a non-steroidal and selective androgen receptor agonist that ACADIA considered part of the class of small molecules called SARMs (selective androgen receptor modulators). ACADIA later presented preclinical data on the compound at the Experimental Biology 2008 meeting, but no subsequent company announcement, investigational new drug filing, or clinical trial registration has been publicly reported since.

No regulatory agency, including the U.S. Food and Drug Administration, has evaluated ACP-105 for safety or efficacy in humans, and no dose, frequency, or route of administration has been established or approved for human use. A search of ClinicalTrials.gov and the peer-reviewed literature does not return a completed or ongoing human trial of ACP-105. Any numbers circulating on retailer websites, forums, or 'research chemical' product listings are not derived from human pharmacokinetic or clinical safety data, and this page will not repeat them as usage suggestions.

What Preclinical Studies Have Actually Tested

The foundational pharmacology of ACP-105 comes from an industry abstract describing its in vitro and in vivo profile, presented at the Experimental Biology meeting and later published in The FASEB Journal. That work reported that in cell-based assays ACP-105 was found to be a potent and selective androgen receptor agonist. In castrated rats, the compound potently suppressed the luteinizing hormone surge and had robust anabolic effects on the levator ani muscle, while tissue specificity was demonstrated in that ACP-105 had minimal trophic effects on prostate in castrated animals and no detectable trophic effect on prostate of intact rats. The same report describes ACP-105 as behaving as a partial androgen receptor agonist, partially reversing the androgenic effect of exogenous testosterone. A separate medicinal chemistry paper covering the same discovery program similarly describes ACP-105 as a novel and potent nonsteroidal selective androgen receptor modulator with partial agonist activity relative to the natural androgen testosterone, noting that in vivo it improved anabolic parameters in a 2-week chronic study in castrated male rats. Quantified head-to-head comparisons of ACP-105's anabolic potency against dihydrotestosterone (of the kind sometimes cited for other SARMs such as S-4/andarine) have not been located for ACP-105 specifically in the available literature, and this page does not repeat unverified numeric ratios.

A separate line of rodent research examined ACP-105 in a very different context: cognitive changes after radiation exposure. A 2011 Brain Research study assessed the potential effects of the SARM ACP-105 in female mice that were either sham-irradiated or irradiated with 137Cesium at a dose of 10 Gy, evaluating rotorod motor performance and cued fear conditioning starting two weeks after irradiation. That study found that irradiation impaired sensorimotor function in vehicle-treated mice but not in ACP-105-treated mice, and that irradiation impaired cued fear conditioning while ACP-105 enhanced fear conditioning in both sham-irradiated and irradiated mice. A related 2013 paper in ACS Chemical Neuroscience examined nonsteroidal SARMs, including ACP-105, together with a selective estrogen receptor beta agonist, in a transgenic mouse model of Alzheimer's disease, evaluating cognitive deficits and amyloid-beta levels. None of this work involved humans, and translation from rodent behavioral or biochemical endpoints to human clinical benefit has not been demonstrated.

A 2025 series of in silico (computer-modeled) toxicology and pharmacokinetic papers has attempted to fill the human-data gap using predictive software rather than laboratory or clinical measurement. One analysis, published in Archives of Toxicology, used seven independent computational platforms and reported that ACP-105 demonstrated high gastrointestinal absorption (up to 100%), moderate lipophilicity (LogP roughly 3.0 to 3.52), and blood-brain barrier penetration predicted in most models, along with strong plasma protein binding (77 to 99%) and a minimal free plasma fraction (under 1%). A companion in silico toxicity paper aimed to use various in silico techniques to predict the toxicity of ACP-105, including acute toxicity, effects on internal organs, genotoxicity based on the Ames test, eye and skin irritation, and cardiotoxicity by testing hERG inhibitors, explicitly stating that the lack of information about the compound in the World Anti-Doping Agency's monitoring program was the motivation for the study. Both papers are explicit that their findings are preliminary structure-based predictions, not confirmed laboratory or clinical pharmacokinetics in a living human body.

Is ACP-105 Legal, and What Is the FDA's Position?

No SARM, including ACP-105, has been approved by the FDA for any human use. According to the U.S. Anti-Doping Agency, there are no Food and Drug Administration-approved SARMs currently available for prescription, and because all SARMs are investigational drugs, it is not legal for a doctor to prescribe one. Case reports on other SARMs note that despite receiving a warning from the FDA and being banned by the World Anti-Doping Agency, SARMs remain readily accessible in the online marketplace, sold as alternatives to anabolic-androgenic steroids.

Products sold online as 'ACP-105' are typically labeled 'for research purposes only' or 'not for human consumption,' a disclaimer that exists to sidestep drug marketing law rather than to make an accurate safety claim. Because these products are not manufactured under pharmaceutical quality control, purchasers have no independent way to confirm the identity, purity, or actual content of what is in the vial, a gap in oversight that exists separately from, and in addition to, the underlying lack of human safety data on the molecule itself. Notably, published sources report differing CAS registry numbers for ACP-105, which underscores how little standardized identity and quality documentation exists for material sold under this name outside controlled research settings.

Doping Status: Why ACP-105 Shows Up in Anti-Doping Testing

Even though it has never been an approved medicine, ACP-105 is monitored in sports drug testing as part of the broader SARM class. Since 2008, SARMs have been included on the World Anti-Doping Agency's Prohibited List in the class of anabolic agents, and they are currently still recognized as doping agents and covered by the WADA Prohibited List in the group S1 Anabolic Agents, subsection 'Other anabolic agents.' Under the U.S. Anti-Doping Agency's summary of that listing, all SARMs are prohibited at all times, both in and out of competition, for every athlete subject to the WADA Code, from elite competitors to recreational athletes.

Analytical chemists have published dedicated papers characterizing ACP-105 specifically for anti-doping purposes. One mass spectrometry paper describes work to expand sports drug testing assays by characterizing the SARM drug candidates RAD140 and ACP-105, noting that some SARMs have been detected in doping control samples despite lacking clinical approval, and that this analytical work also extended to non-human sample types used in equine drug testing. A more recent in silico toxicology paper states plainly that the lack of information about ACP-105 in WADA's monitoring program was the direct motivation for that research, illustrating that anti-doping and forensic toxicology interest in the compound has continued even though it was never marketed as a medicine.

For any competitive athlete, the practical implication is that using ACP-105 in any dose or form creates doping-violation risk regardless of intent, source, or whether the product was purchased as a labeled 'research chemical.'

Documented Harms Associated With SARM Use in Humans

Because ACP-105 itself has not been studied in human trials, there is no compound-specific human adverse-event data to report. The harms documented for the SARM class as a whole are relevant context, since ACP-105 shares the same androgen-receptor mechanism and is marketed through similar unregulated channels as SARMs with more human exposure, such as enobosarm (ostarine), LGD-4033 (ligandrol), and RAD-140.

LiverTox, the NIH's reference resource on drug-induced liver injury, describes SARMs generally as orally available, synthetic, nonsteroidal drugs that bind androgen receptors with tissue-selective activity, and notes that several such agents were developed and evaluated as therapy for cancer cachexia, osteoporosis, and bone and muscle wasting with aging, but that none were approved for human use. The same resource documents case reports of men who presented with jaundice two and four months after starting unknown doses of ligandrol and RAD-140, with bilirubin, ALT, and alkaline phosphatase elevations that gradually improved after the drugs were stopped and toxicologic analysis confirmed the SARMs without other contaminants.

Multiple published case reports describe SARM-associated liver injury requiring medical attention. One case report describes a patient who developed jaundice and elevated liver enzymes after three months of RAD-140 use, with a liver ultrasound showing hepatic steatosis, and with symptoms resolving only after discontinuing the drug. A separate case published in the Ochsner Journal describes a 24-year-old man who developed abdominal pain, jaundice, and pruritus after five weeks of RAD-140 use, with a cholestatic pattern of liver injury and a peak total bilirubin of 38.5 mg/dL, and a liver biopsy supporting a diagnosis of RAD-140-associated liver injury. A case series published in Hepatology Communications similarly documents jaundice, anorexia, and weight loss in men who had used ligandrol or RAD-140, including one patient whose investigations showed a mixed hepatocellular-cholestatic pattern of liver injury. These reports collectively illustrate that despite the tissue-selectivity rationale underlying SARM design, off-target hepatic effects have occurred in real-world use of several SARMs.

None of these reports isolate ACP-105 specifically, since it has essentially no reported human use documented in medical literature, only forensic detection in doping-control and equine drug-testing samples. That absence of case reports should not be read as evidence of safety; it reflects the near-total absence of monitored human exposure, which is itself the central problem with using an unapproved investigational compound outside a supervised clinical trial.

What Would Have to Happen Before a Real Dosing Answer Exists

Establishing a legitimate human dose for any drug candidate normally requires sequential Phase 1 safety and pharmacokinetic trials in healthy volunteers, followed by Phase 2 and 3 efficacy and safety trials in the target patient population, conducted under an investigational new drug application reviewed by the FDA or an equivalent regulator. Other SARMs, including ligandrol and enobosarm, have been carried further through this pipeline and have undergone limited human trials in aging or muscle-wasting research contexts, illustrating what a structured, monitored dose-escalation study looks like. No equivalent published human trial exists for ACP-105. A search of ClinicalTrials.gov and the peer-reviewed literature does not return a completed or ongoing human study of the compound. Until such trials exist and are published, any specific numeric dose, frequency, or duration attached to ACP-105 in a commercial or forum context is not derived from verified human evidence.

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