Looking at PT-141 vs Addyi starts with how you take them and who each brand is labeled to treat. Branded Vyleesi contains bremelanotide, also called PT-141, and is an as-needed injection under the skin. Branded Addyi contains flibanserin and is a tablet taken every night at bedtime.
Their age rules differ in an important way. The current Vyleesi prescribing information on DailyMed (Revised: 3/2024) covers only premenopausal women. The current Addyi prescribing information on DailyMed (Revised: 12/2025) covers women under 65, including women after menopause.
Both brands treat acquired, generalized hypoactive sexual desire disorder (HSDD), meaning low desire that causes marked distress or interpersonal difficulty. Acquired means low desire started after a normal period, and generalized means it happens across partners and situations. Neither medicine is a hormone or a blood-flow pill, and they are not interchangeable.
PT-141 vs Addyi at a glance
Both labels rule out low desire caused by another health condition, relationship trouble, or a medication or drug. Vyleesi's label states that "VYLEESI is not indicated for the treatment of HSDD in postmenopausal women or in men" in Section 1. Addyi's label states that "ADDYI is not indicated in men" and "ADDYI is not indicated to enhance sexual performance" in Section 1.
Vyleesi is not for performance enhancement either, and PT-141 for men covers the separate male studies. Both labels also direct clinicians to stop after eight weeks without symptom improvement. That rule is a check-in with your doctor, not a promise of results by week eight.
| Label point | Vyleesi (bremelanotide / PT-141) | Addyi (flibanserin) |
|---|---|---|
| Label revision | Revised: 3/2024 |
Revised: 12/2025 |
| Indicated group (§1) | Premenopausal women with acquired, generalized HSDD | Women under 65 with acquired, generalized HSDD, including after menopause |
| Not indicated for (§1) | Men, postmenopausal women, performance enhancement | Men, performance enhancement (age 65+ is outside the indication) |
| Route and schedule | As-needed injection under the skin | Oral tablet every night at bedtime |
| Mechanism (§12.1 / §12.2) | §12.1: activates melanocortin receptors (MC1R, MC4R); HSDD mechanism unknown | §12.1: HSDD mechanism not known; §12.2: lab binding to serotonin 5-HT1A and 5-HT2A receptors |
| Contraindications (§4) | Uncontrolled high blood pressure; known heart or blood-vessel disease | Moderate or strong CYP3A4 inhibitors (slow drug breakdown); liver impairment; known allergy |
| Main warnings (§5) | Temporary blood-pressure rise and slower pulse; nausea; skin darkening | Boxed warning for severe low blood pressure and fainting; alcohol rules; liver and drug risks; drowsiness |
| Key interaction (§7) | Slows stomach emptying; avoid oral naltrexone used for alcohol or opioid addiction | Contraindicated with moderate or strong CYP3A4 inhibitors (medicines that slow flibanserin breakdown); other sedating medicines can increase sedation |
| 8-week stopping rule | "Discontinue VYLEESI after 8 weeks if the patient does not report an improvement in her symptoms" | "Discontinue ADDYI after 8 weeks if the patient does not report an improvement in her HSDD symptoms" |
How the mechanisms and routines differ
Neither label claims to know the exact brain pathway that improves low desire. In Section 12.1, Vyleesi's label states that "The mechanism by which VYLEESI improves HSDD in women is unknown" in clinical use. Bremelanotide is a melanocortin-receptor agonist, meaning it activates docking sites on cells.
At treatment levels, two docking sites matter most: MC4R on nerve cells and MC1R on skin-pigment cells. Our guide on how PT-141 works explains that biology in plain terms.
Addyi's Section 12.1 similarly states that its HSDD mechanism is not known. Separately, Section 12.2 describes laboratory binding to serotonin receptors, activating 5-HT1A and blocking 5-HT2A.
Blood pressure, alcohol, and side effects
The two labels warn about opposite blood-pressure shifts. Vyleesi is contraindicated in people with uncontrolled high blood pressure or known cardiovascular (heart or blood-vessel) disease. It is also not recommended for patients at high risk for cardiovascular disease.
Section 5.1 reports maximal study increases of 6 mmHg systolic (top number) and 3 mmHg diastolic (bottom number), peaking two to four hours post-dose. Heart rate dropped up to 5 beats per minute, and both readings usually returned to baseline within 12 hours. Study figures do not cap individual responses, as covered in PT-141 and blood pressure.
Section 5.2 reports focal hyperpigmentation (darkening of the face, gums, or breasts) in 1% with up to eight monthly doses versus 0% on placebo. In a daily-use study, 38% (nearly 2 in 5) developed darkening after eight days, and 14% more did over eight further days. Risk rose with darker skin, and darkening was not confirmed to fade in all patients after stopping.
Nausea affected 40% of women (2 in 5) on Vyleesi, leading 13% to use anti-nausea medicine and 8% to stop early. The label advises considering discontinuation if nausea is persistent or severe. Patients should also avoid Vyleesi with oral naltrexone for alcohol or opioid addiction, because slower stomach emptying can cause naltrexone treatment failure.
Addyi's boxed warning highlights severe hypotension (low blood pressure) and syncope (fainting). Following an April 11, 2019 order, an October 9, 2019 FDA supplement letter revised Addyi's alcohol warning, and a companion October 9, 2019 FDA REMS letter ended special prescriber and pharmacy certification. In that review, Phase 1 studies showed that waiting at least two hours after one or two drinks reduced fainting risk.
Today's boxed warning says "to wait at least two hours after consuming one or two standard alcoholic drinks" before taking Addyi at bedtime. It also says "to skip their ADDYI dose if they have consumed three or more standard alcoholic drinks" that evening. Section 5.1 adds that patients should "not use alcohol until the following day" after bedtime dosing.
One standard drink equals 14 grams of alcohol: 12 ounces of 5% beer, 5 ounces of 12% wine, or 1.5 ounces of 40% spirits. Addyi is contraindicated with moderate or strong CYP3A4 inhibitors (medicines that slow flibanserin breakdown) and with any degree of liver impairment. Both raise flibanserin levels in the blood and can cause severe low blood pressure and fainting.
Addyi's label advises avoiding driving or other activities requiring full alertness until at least six hours after a dose. That restriction also applies until the patient knows how Addyi affects them. Near-fainting requires lying flat immediately and prompt medical help if symptoms do not resolve; actual fainting also requires prompt medical attention.
| Label table and group | Active drug | Matching placebo |
|---|---|---|
| Vyleesi nausea (premenopausal) | 40.0% | 1.3% |
| Vyleesi flushing (premenopausal) | 20.3% | 0.3% |
| Vyleesi grouped injection-site reactions (premenopausal) | 13.2% | 8.4% |
| Addyi dizziness (premenopausal) | 11.4% | 2.2% |
| Addyi somnolence / drowsiness (premenopausal) | 11.2% | 2.9% |
| Addyi nausea (premenopausal) | 10.4% | 3.9% |
| Addyi dizziness (postmenopausal under 65) | 7.9% | 3.3% |
| Addyi somnolence / drowsiness (postmenopausal under 65) | 7.7% | 1.8% |
| Addyi nausea (postmenopausal under 65) | 6.6% | 3.9% |
As Vyleesi's Section 6.1 notes, side-effect rates from separate clinical trial programs cannot be directly compared across drugs.
What the RECONNECT and VIOLET trials found
The cited RECONNECT and VIOLET trials were separate placebo-controlled studies; they do not establish which medication works better. The 2019 RECONNECT phase 3 paper in Obstetrics & Gynecology combined two 24-week trials in premenopausal women with HSDD (average age 39). Across both studies, 1,267 women were randomly assigned, with 1,247 in the safety review and 1,202 in the effectiveness analysis.
Participants answered standard questionnaires measuring sexual desire (the Female Sexual Function Index, or FSFI) and personal distress. Compared with placebo, bremelanotide improved desire ("integrated studies 0.35, P<.001") and lowered distress ("integrated studies −0.33, P<.001") over 24 weeks.
Even so, the change in monthly satisfying sexual events did not differ significantly from placebo (0.0 vs −0.1, P=.630). Drug-sponsor involvement and narrow enrollment rules also limit broad generalization, as covered in PT-141 clinical trials.
The 2012 VIOLET trial in The Journal of Sexual Medicine tested 24 weeks of nightly flibanserin in premenopausal women with HSDD. Participants took placebo (295 women), a lower nightly flibanserin strength (295), or a higher nightly strength (290). Both flibanserin groups improved satisfying sexual events (P<0.05 and P<0.01) and FSFI desire scores (P<0.05), while the higher strength also reduced distress (P<0.001).
Meaningful overall improvement was reported by "39.6% and 50.0% vs. 30.3%, respectively" (up to half on flibanserin versus 3 in 10 on placebo). Still, on daily electronic-diary desire, "statistical significance was not reached (P = 0.07 vs. placebo)" in VIOLET, as Addyi's Section 14.1 also notes. Addyi's Section 14.2 also describes a 24-week trial in postmenopausal women under 65 (447 Addyi, 455 placebo).
Compounded PT-141, recent FDA actions, and clinical review
Promise does not offer Addyi or flibanserin. PT-141 prescribed through Promise is dispensed by a licensed U.S. compounding pharmacy. PT-141 is dispensed by a licensed U.S. compounding pharmacy as a compounded medication, which is different from an FDA-approved product: the formulation offered here is not FDA-approved.
As the FDA's compounding questions and answers page explains, the agency does not verify the safety, effectiveness, or quality of compounded drugs before marketing. Branded Vyleesi's review (first cleared in the U.S. in 2019) does not carry over to a compounded preparation. In appropriate cases, compounding can serve an important patient need when a doctor prescribes it.
As of October 17, 2026, the day this article was written, recent FDA notices show why a prescription path matters for both molecules. An FDA warning letter dated August 24, 2026 cited an online seller's PT-141 among unapproved new drugs. On August 25, 2026, an FDA public notification on WAP Sensual Enhancement reported hidden flibanserin, yohimbine, and tadalafil in tested retail samples.
Neither notice changed Vyleesi's or Addyi's label, while a prescribed medication provides a named prescriber and a licensed dispensing pharmacy to contact. A licensed provider may still prescribe a compounded formulation — that decision is between you and your doctor. At Promise, a licensed provider reviews every request, and not everyone qualifies.
