PT-141 skin darkening is a real reported side effect. It can affect the face, gums, and breasts, and it may not completely fade after treatment stops. The clearest figures come from Vyleesi, the branded medicine containing bremelanotide, also called PT-141. They aren't exact predictions for every compounded prescription.
The medical term is focal hyperpigmentation: patches of darker coloring in particular areas. That is different from an even tan. It also means a new dark patch deserves attention even when it isn't painful.
PT-141 skin darkening: what the label reports
About 1 in 100 Vyleesi-treated participants reported pigment changes, compared with none receiving placebo, an inactive comparison treatment. The label describes patients receiving up to eight doses per month. Its combined safety table includes 627 treated women and 620 placebo recipients. The percentage describes people, not injections.
Those observations sit within RECONNECT, two 24-week trials in women before menopause with distressing low sexual desire. Kingsberg and colleagues, Obstetrics & Gynecology, 2019, reported 1,267 women randomly assigned to bremelanotide or placebo, with 1,247 receiving study medicine. Most participants were White. The findings don't establish a separate rate for men.
As of November 5, 2026, the day this article was written, the FDA's Vyleesi label reads “Revised: 10/2026.” Its skin-darkening warning remains, including the possibility that patches may not completely clear. The pigment figures in it still come from the original trials.
The Vyleesi label walkthrough covers the other sections; the pigment warning is a specific reason for follow-up.
Where were Vyleesi dark spots reported?
The reported areas include the face, gums, and breasts. Gingiva, the label's word for gums, means the tissue around the teeth. The reports therefore weren't limited to redness or bruising where an injection entered the skin.
Bremelanotide activates melanocortin receptors, docking points on cells that receive chemical signals. One is called MC1R. It appears on melanocytes, the cells that make melanin, the pigment that gives skin its color. Activating that docking point can increase pigment production.
That explains why a medicine studied for sexual desire can also affect coloring. It doesn't establish that every new spot has the same cause. A clinician still needs to assess the location, timing, and appearance.
Why daily exposure produced different numbers
The DailyMed label's section 5.2 describes another study with daily exposure. Nearly 2 in 5 participants, or 38%, developed focal pigment changes after eight consecutive days. Among those continuing for eight more consecutive days, an additional 14% developed new changes.
That isn't the same exposure pattern as occasional use. It isn't a reason to add the figures into a personal risk estimate, either. The label doesn't give the daily-study group sizes in that paragraph. It also does not recommend more than eight monthly doses of Vyleesi. These are brand-label facts; the prescriber sets the actual compounded prescription.
A separate intensive-exposure experiment reinforces why context matters. Spana and colleagues, Diabetes, Obesity and Metabolism, 2022, studied women with obesity. In Study A, participants received injections three times daily for 15 days. Skin hyperpigmentation was reported in 19 of 30 treated women, about 63%, versus 2 of 28 receiving placebo, about 7%.
That small experiment used a substantially different schedule and wasn't a study of ordinary Vyleesi use. Its authors also noted the lack of follow-up after treatment ended. Its percentage cannot replace the label's occasional-use figure or answer whether patches eventually faded.
Does skin tone change the risk?
The label reports greater risk in people with darker skin. It doesn't provide a reliable percentage for each skin tone or a test that predicts who will develop a patch.
The warning isn't limited to people with darker skin. A low overall rate doesn't mean lighter skin is protected.
The useful discussion includes usual coloring and any existing patches. A change that looks small to someone else can still matter greatly to the person living with it.
Is PT-141 pigmentation permanent?
Lasting changes are possible, but there isn't a dependable percentage for permanent pigmentation. The label says clearing wasn't confirmed in everyone after treatment stopped. That wording supports uncertainty about persistence; it doesn't prove that every unresolved patch remained forever.
The FDA's original clinical review, in its benefit-risk assessment, documented reversal in about half the phase 3 cases during follow-up. That leaves an important distinction: confirmed fading in some people and incomplete information about others.
A promise that every patch disappears within a few weeks goes beyond those findings. So does claiming that any patch is necessarily permanent. The studies don't provide a dependable fading timetable for an individual, particularly someone receiving a different preparation.
Why this isn't evidence for tanning
A pigment effect doesn't establish a cosmetic benefit. The reports describe uneven changes in specific areas, including gum tissue, rather than a predictable whole-body tan.
Calling darker coloring a sign that PT-141 is “working” also confuses a side effect with the intended treatment outcome. RECONNECT measured desire and distress through questionnaires. It didn't use skin color as a measure of benefit. The PT-141 myths guide checks the broader claims about the molecule.
PT-141 prescribed through Promise is dispensed by a licensed U.S. compounding pharmacy as a compounded medication, meaning a preparation made for an individual prescription. This is different from Vyleesi, the FDA-approved bremelanotide product: the formulation offered here is not FDA-approved. The FDA's compounding explanation describes that distinction. A licensed provider may still prescribe — that decision is between you and your doctor.
What a prescriber assesses when coloring changes
The useful details are when the change began, where it appeared, whether it is spreading, and the actual prescription and how often it was used. The clinician considers other explanations and whether treatment still fits the person's needs. New coloring belongs in that assessment even when other side effects have been mild.
Section 5.2 tells prescribers to consider discontinuing Vyleesi if hyperpigmentation develops. That decision includes how much the appearance matters to the patient and the uncertain prospect of complete fading. The broader PT-141 side-effects guide covers the separate nausea and blood-pressure questions.
At Promise, a licensed provider reviews every request, and not everyone qualifies. Follow-up gives that clinician a way to review a visible change alongside the original reason for treatment.
