Last reviewed 15 September 2026. Products on this site are supplied strictly for laboratory research and are not for human consumption. This guide summarises published research; it is not medical advice.
What ACP-105 is
ACP-105 is a non-steroidal selective androgen receptor modulator developed by Acadia Pharmaceuticals in California in the mid 2000s. Chemically it is a small molecule unrelated to the aryl-propionamide family that produced Ostarine, Andarine and S-23; it came out of a separate screening programme looking for compounds that would activate the androgen receptor in muscle and bone while leaving the prostate and other androgen-sensitive tissues comparatively untouched. In the published characterisation ACP-105 is described as a partial agonist: it binds the androgen receptor with high affinity but produces a smaller maximal response than testosterone or dihydrotestosterone. That partial-agonist profile is the reason it attracted interest, and it is also the reason it is sometimes compared with LGD-4033, which is a full agonist at the same receptor.
What the research studied
The principal publication is Schlienger and colleagues (2009) in the Journal of Medicinal Chemistry, in which Acadia's chemists reported the synthesis of the compound series, its binding data and its activity in cell-based assays and in castrated male rats. The rat work used the standard Hershberger model, in which the weight of the levator ani muscle stands in for anabolic activity and the weight of the prostate and seminal vesicles stands in for androgenic activity. ACP-105 increased levator ani weight in a dose-dependent way while producing a much smaller effect on prostate weight, which is the pattern every SARM programme was chasing. The same paper reported oral bioavailability in rodents and a potency in the low nanomolar range at the receptor. Acadia presented further preclinical data at conferences on bone density in ovariectomised rats, again showing an anabolic effect on bone with limited prostate stimulation.
Acadia did not take ACP-105 into human trials. The company's pipeline moved towards neuropsychiatry and the SARM programme was not pursued, so ACP-105 sits with S-23 and Andarine as a compound whose entire evidence base is animal and cell work from a single sponsor.
What has not been studied
There are no published human trials of ACP-105 of any kind: no pharmacokinetic study, no safety study, no efficacy study. Its effect on natural testosterone production in people, on lipids, on the liver and on the heart has never been measured. The rodent data show the expected suppression of the hormones that drive endogenous testosterone at active doses, and whether that suppression recovers on withdrawal, and how quickly, is unknown in humans. There is also very little independent replication: almost everything published on ACP-105 comes from Acadia or its collaborators. For a research buyer the practical consequence is that any claim about what the compound does in people is anecdote, and that the compound's strength relative to others is a statement about receptor binding in a dish, not about outcomes.
How it compares
| Compound | Receptor activity (published) | Highest study stage | Primary research aim |
|---|---|---|---|
| ACP-105 | High affinity, partial agonist | Preclinical (rat) | Muscle and bone, low prostate effect |
| LGD-4033 | High affinity, full agonist | Phase I | Muscle wasting |
| Ostarine (MK-2866) | Moderate | Phase III | Muscle wasting |
| S-23 | Very high | Preclinical (rat) | Male contraception, lean mass |
| Andarine (S-4) | Moderate | Preclinical | Muscle and bone |
The legal position in the UK, 2026
ACP-105 is not a controlled drug under the Misuse of Drugs Act 1971. It is not a licensed medicine, so it cannot be sold for human consumption; the Medicines and Healthcare products Regulatory Agency treats any product supplied with dosing instructions or health claims as an unlicensed medicine. It may be sold as a research chemical. In sport it is prohibited at all times under WADA class S1.2 (other anabolic agents). Buyers outside the UK should check local rules; Australia schedules SARMs as prescription-only medicines and several EU states restrict import. Full guide: Are SARMs legal in the UK?
What to check on a research product
Because ACP-105 has no human data, the specification on the bottle is the only thing a buyer can verify. Check the strength per capsule, the capsule count and the batch number, and match the batch to its certificate of analysis. Every Dexterz Labs batch is independently tested and its certificate is published on the Lab Testing page. See how to read a certificate of analysis.
Key references
Schlienger N, Lund BW, Pawlas J, et al. Synthesis, structure-activity relationships, and characterization of novel nonsteroidal and selective androgen receptor modulators. Journal of Medicinal Chemistry. 2009;52(24):7186-7191. Narayanan R, Coss CC, Dalton JT. Development of selective androgen receptor modulators (SARMs). Molecular and Cellular Endocrinology. 2018;465:134-142. World Anti-Doping Agency. Prohibited List 2026, S1.2.
Related guides and products
Dexterz Labs ACP-105 5 mg, 90 capsules (research use only) · LGD-4033 · Ostarine · S-23 · Andarine · Are SARMs legal in the UK? · Reading a certificate of analysis · SARMs 101
Related peptides in the research
Readers comparing SARMs with the peptide literature usually turn to the tissue-repair peptides next: BPC-157 and TB-500, both studied in rodent tendon, ligament and wound models, and the two together in the Wolverine blend. For how the two classes differ in mechanism, evidence and storage, read SARMs vs peptides. Full range: Origin Peptides range.