Is HMI-115 Considered a Safe Option, or Does It Have Strong Side Effects?

HMI-115 has drawn increasing attention in recent years as a possible new pathway in hair loss treatment. Unlike minoxidil, which stimulates blood flow to the scalp, or finasteride, which blocks the conversion of testosterone into dihydrotestosterone, HMI-115 belongs to a completely different category. It is a gonadotropin-releasing hormone (GnRH) antagonist, meaning it acts on the pituitary gland, the organ that coordinates many of the hormones in our bodies. Because of this, the discussion about safety becomes more complex, as this drug influences more than just hair growth.

What Makes HMI-115 Different?

The main interest in HMI-115 lies in its mechanism. GnRH is a hormone produced in the brain that signals the pituitary gland to release two key reproductive hormones: luteinizing hormone (LH) and follicle-stimulating hormone (FSH). These, in turn, regulate estrogen and testosterone. By blocking the GnRH receptor, HMI-115 alters hormone signaling. Researchers became interested in this pathway after noticing that when reproductive hormones are suppressed, hair follicle activity sometimes improves. In theory, this means that a GnRH antagonist could promote hair growth in conditions such as androgenetic alopecia. But the same pathway that holds promise also raises concerns, because manipulating the hormonal system may trigger widespread effects.

To understand whether HMI-115 is safe or not, we need to examine the available studies critically. Research is still limited, and most of what exists comes from company-sponsored work. This means that while the early findings are intriguing, they must be read with caution.

2021: Trials in Endometriosis Patients

In 2021, Hope Medicine began a Phase II trial of HMI-115 in women with endometriosis. Endometriosis is a painful condition where tissue similar to the lining of the uterus grows outside it, causing inflammation and infertility. In this trial, participants received repeated HMI-115 injections over several months. Outcomes were measured through hormone blood tests, imaging, and patient-reported pain scores. The trial reported a reduction in symptoms, suggesting that the drug was effective in lowering hormone-driven pain. However, side effects included hot flashes, irregular bleeding, and mood changes. **All of these are signs of systemic hormonal disruption. The key limitation here is that this trial did not include hair loss patients, so we cannot assume that results translate directly to people seeking treatment for alopecia. The study also lacked long-term safety data, which is crucial when dealing with reproductive hormones.

2022: Preclinical Studies in Monkeys

In 2022, a preclinical study tested HMI-115 in cynomolgus monkeys, a species whose hormonal system closely resembles that of humans. The monkeys received injections of HMI-115 over several months, and researchers observed changes in hair growth as well as hormone levels. The results suggested that hair density increased under treatment. However, this came with changes in reproductive hormone profiles. Animal studies like this provide valuable insights but are never definitive, since human physiology can respond differently. **This raises a concern: if even non-human primates show systemic hormone changes, humans might experience similar or stronger effects. **

2023: Early Trials in Pattern Hair Loss

In late 2023, Hope Medicine announced that it had started trials for androgenetic alopecia, the most common type of hair loss. Participants, both men and women, received monthly injections of HMI-115 for six months. Outcomes were evaluated with standardized scalp photography and hair density counts. According to the company’s reports, some participants showed visible regrowth. However, side effects such as hot flashes, fatigue, and mild mood changes were also reported. Since the study was funded and communicated by the company itself, without peer-reviewed publication, there is a risk of bias. The small sample size and short duration add further limitations. At this stage, these findings cannot be considered definitive evidence of safety. (Hope Medicine, 2023, reported on Tressless).

Why Hormonal Side Effects Matter

Unlike minoxidil, which is applied topically and has largely local effects, HMI-115 works through systemic hormonal control. GnRH controls the entire reproductive axis. Blocking it can lower estrogen, progesterone, and testosterone. This explains why patients report symptoms that resemble menopause or low testosterone, including hot flashes, fatigue, mood shifts, and irregular menstrual cycles. These are not minor inconveniences; they indicate that the drug fundamentally changes how the body regulates its hormones. For a hair loss treatment, this level of systemic involvement raises serious concerns.

The Verdict: Safer Than Expected or Too Risky?

So, is HMI-115 a safe option or one with strong side effects? Based on what we know so far, it cannot yet be classified as safe. The evidence points clearly to its effectiveness in stimulating hair growth, at least in early trials, but this comes with strong hormonal side effects. The lack of independent, long-term, peer-reviewed studies means we simply do not know how dangerous the risks may be. If we are thinking about whether to use such a treatment ourselves, the current answer is that the promise of hair regrowth must be weighed against the possibility of significant hormonal disruption. This trade-off is not trivial, and for many people, the risks could outweigh the benefits

HMI-115 is not yet a safe, established treatment. It shows potential in promoting hair regrowth, but it also clearly disrupts hormone balance, leading to strong side effects. Until large, independent, long-term clinical trials are published and reviewed, HMI-115 remains an experimental option whose risks cannot be ignored.

References

erfect Hair Health article on HMI-115 (covers mechanism, phase 1 info, provisional safety)

Published May 9 2024, updated Oct 23 2024

Link: https://perfecthairhealth.com/hmi-115-what-we-know-so-far/

Perfect Hair Health

Hope Medicine press release on Phase II endometriosis results (interim results, safety, hormone data)

Published Oct 24 2024 via PR Newswire

Link: https://www.hopemedinc.com/company-release-40

hopemedinc.com

ClinicalTrials.gov listing for the phase 2 study in endometriosis (design, participants, timeline)

Study NCT05101317

Link: https://clinicaltrials.gov/study/NCT05101317

centerwatch.com ClinicalTrials.gov

Press release on Phase Ib study in androgenetic alopecia (efficacy and safety in 12 males and 4 females)

Published Jan 14 2024 via PR Newswire / BioSpace

Link: https://www.biospace.com/positive-outcome-from-a-phase-ib-study-in-australia-treating-patients-with-androgenic-alopecia

BioSpace

ClinicalTrials.gov listing for the phase 2 AGA (male pattern hair loss) study (completed)

Study NCT06118866

Link: https://clinicaltrials.gov/study/NCT06118866

Hope Medicine press release on FDA clearance for Phase II in alopecia (IND approval, trial plan)

Published Jan 26 2022 via PR Newswire

Link: https://www.hopemedinc.com/company-release-5