Encyclopedia · growth stimulant
HMI-115
An injected antibody that blocks the prolactin receptor, with a small open-label hair gain and an unreported 192-man phase 2 trial in men.
What it is
HMI-115 is a monoclonal antibody from Hope Medicine (Nanjing) that blocks the prolactin receptor, a route that does not depend on androgens. A 2026 review groups it with Absci's ABS-201 as biologics that inhibit the prolactin receptor (Agrawal 2026). It is not approved anywhere and would be prescription-only. The company has since moved the drug toward endometriosis.
What the studies show
- An open-label 24-week phase 1b in Australia enrolled 16 people (12 men, 4 women). The company reported an average gain of 14 non-vellus hairs/cm2 in the men, with no control group (trial record).
- A randomised, double-blind, placebo-controlled phase 2 of 192 men for 24 weeks completed in August 2024, and no results have been posted or published that we found (trial record).
- The evidence is early and uncontrolled, and the registry shows no pattern-hair-loss phase 3.
Side effects and safety
- Safety for the hair studies has not been reported. Blocking prolactin signalling has hormonal consequences that would matter for women and pregnancy.
Bottom line
An interesting biologic, but the phase 2 result is unknown, so wait for data. Absci's competing antibody ABS-201 has a 26-week readout planned for early 2027; see the hair growth pipeline. Discuss with a doctor.
Studies 3
ClinicalTrials.gov NCT05324293. Phase 1b study of HMI-115 in androgenetic alopecia. Hope Medicine
Tested: HMI-115 anti-prolactin-receptor antibody injections, open-label
Result: The company reported an average gain of 14 non-vellus hairs/cm2 in the men; no control group.
Read the study ↗ClinicalTrials.gov NCT06118866. Phase 2 study of HMI-115 in men with androgenetic alopecia. Hope Medicine
Tested: HMI-115 vs placebo
Result: Completed 26 August 2024; no results have been posted or published.
Read the study ↗Agrawal A et al. Emerging pharmacotherapies for androgenetic alopecia. Expert Opin Pharmacother. 2026
Tested: emerging drugs including HMI-115, ABS-201, KB-141
Result: Groups HMI-115 and ABS-201 as antibodies that block the prolactin receptor, a route that does not depend on androgens.
Read the study ↗Related
- MinoxidilThe most widely used hair-growth treatment, available as a cheap over-the-counter lotion or foam and as a prescription tablet, with a mechanism that is still only partly understood.
- FinasterideA prescription pill (and in some countries a scalp spray) that lowers DHT and is the best-proven drug for stopping male pattern hair loss.
- Hair growth pipeline (2026)What is in clinical trials for hair loss as of October 2026, how far along it is, and how much to trust the early numbers.