PT-141 (Bremelanotide) + Egrifta (Tesamorelin): When to Pick One Over the Stack

Start with the labels, not the stack

Both drugs are peptides given by subcutaneous injection, and both have FDA-approved products: Vyleesi for bremelanotide and Egrifta SV and WR for tesamorelin [1][2][3]. Beyond that they have little in common in the clinic.

The Vyleesi label covers one thing: premenopausal women with acquired, generalized HSDD — low sexual desire that causes marked distress or interpersonal difficulty and is not due to a co-existing medical or psychiatric condition, problems with the relationship, or the effects of a medication or drug [1]. The same label states the drug is not indicated for postmenopausal women, not indicated for men, and not indicated to enhance sexual performance [1].

The Egrifta labels cover one thing: reduction of excess abdominal fat in HIV-infected adults with lipodystrophy [2]. The label adds that the drug is not indicated for weight loss management because it has a weight-neutral effect, and that long-term cardiovascular safety has not been established [2].

Put together, the only person who fits both labels is a premenopausal woman with HIV and lipodystrophy who also has HSDD not explained by another condition, her relationship, or a medication. For a man, for a postmenopausal woman, or for anyone without HIV lipodystrophy, at least one half of the stack sits outside its labeled use.

What each drug does and how it is used

Bremelanotide

Bremelanotide is a cyclic peptide of 7 amino acids and a melanocortin receptor agonist. It activates several receptor subtypes, in this order of potency: MC1R, MC4R, MC3R, MC5R, MC2R. At the approved dose, binding at MC1R and MC4R is most relevant, and how the drug improves HSDD is unknown [1]. MC1R is expressed on pigment cells (melanocytes), and binding there increases pigmentation [1].

The dose is 1.75 mg injected under the skin of the abdomen or thigh with a prefilled autoinjector, as needed, at least 45 minutes before anticipated sexual activity. No more than one dose in 24 hours, and more than 8 doses per month is not recommended [1]. The Vyleesi label says to stop treatment after 8 weeks if symptoms have not improved [1].

Tesamorelin

Tesamorelin is a synthetic analog of human growth hormone-releasing factor (GHRF, also called GHRH): the 44-amino-acid human sequence with a hexenoyl group on the N-terminal tyrosine. It is a peptide, not growth hormone [2]. It binds pituitary GRF receptors and drives the pituitary to release the body's own growth hormone, which raises IGF-1 and IGFBP-3 [2].

There are two current products and they are dosed differently. Egrifta SV is 1.4 mg once daily into the abdomen and uses the supplied Sterile Water for Injection diluent; the reconstituted dose is given immediately [2]. Egrifta WR is 1.28 mg once daily from an 11.6 mg vial reconstituted with 1.3 mL of Bacteriostatic Water, with one vial supplying 7 daily doses [3]. The labels state the two are not substitutable [3]. The 2 mg daily dose used in the pivotal trials belonged to the older 1 mg-per-vial product; the SV and WR doses were accepted because their exposure is similar to that 2 mg dose [2][3].

What the trials measured

In bremelanotide's two identical phase 3 trials (RECONNECT, 24 weeks), 1,267 premenopausal women with HSDD were randomized and 1,202 were in the efficacy analysis. Compared with placebo, bremelanotide improved desire scores by 0.30 points in study 301, 0.42 in study 302, and 0.35 across both studies [4], and desire-related distress fell by 0.37, 0.29 and 0.33 points [4]. On the label's own table, mean desire change from baseline was 0.5 vs 0.2 in study 1 and 0.6 vs 0.2 in study 2 [1]. There was no significant difference in the number of satisfying sexual events [4].

For tesamorelin, Study 1 (412 HIV-infected adults, 26 weeks) found visceral fat fell 15.2% on tesamorelin and rose 5.0% on placebo, triglycerides fell 50 mg/dL vs rose 9 mg/dL, and the total-to-HDL cholesterol ratio fell 0.31 vs rose 0.21 [5]. Study 2 (404 patients) found visceral fat fell 10.9% (-21 cm2) vs 0.6% (-1 cm2) on placebo [6]. Pooled across both trials (806 patients), visceral fat changed by -24 vs +2 cm2, a treatment effect of -15.4% [7]. When people treated with tesamorelin for the first 26 weeks were switched to placebo for weeks 26 to 52, visceral fat rose 16% to 22%, against 0% to -5% in those who stayed on tesamorelin [2].

What each label says about interactions and monitoring

Each label's interaction advice is separate. For Vyleesi, the label says it may slow stomach emptying and reduce absorption of oral medicines, so it should be avoided with oral drugs that depend on threshold blood levels, such as antibiotics. It also says Vyleesi may significantly decrease levels of oral naltrexone used for alcohol or opioid addiction, and to avoid that combination [1]. The Egrifta labels say growth hormone may alter CYP450-mediated clearance of drugs such as corticosteroids, sex steroids, anticonvulsants and cyclosporine, and that people on glucocorticoid replacement may need higher maintenance or stress doses [2].

The side effects that decide which one a person can take

Bremelanotide's label leads with blood pressure. Each dose causes a transient rise and a fall in heart rate: maximal increases of 6 mmHg systolic and 3 mmHg diastolic, peaking 2 to 4 hours after the dose, with heart rate down up to 5 beats per minute and values usually back to baseline within 12 hours [1]. In a separate 8-day ambulatory study of 127 women dosed daily, mean daytime blood pressure rose 1.9 mmHg systolic and 1.7 mmHg diastolic [1]. The drug is contraindicated in uncontrolled hypertension or known cardiovascular disease and is not recommended in people at high cardiovascular risk [1]. Nausea affected 40% of patients vs 1.3% on placebo, 8% stopped the trials because of it, and pre-treating with oral ondansetron did not reduce it [1]. Focal hyperpigmentation, including on the face, gums and breasts, was reported by 1% of patients using up to 8 doses a month, but by 38% of patients after 8 consecutive days of daily dosing [1].

Tesamorelin's label leads with growth factor and glucose. Among patients treated 26 weeks, 47% had IGF-1 above 2 SDS and 36% above 3 SDS; among those treated 52 weeks, 34% and 23% [2]. HbA1c of 6.5% or higher developed in 5% on tesamorelin vs 1% on placebo, a hazard ratio of about 3.3 (95% CI 1.4 to 9.6) [2]. It is contraindicated in active malignancy, pregnancy, disruption of the hypothalamic-pituitary axis, and known hypersensitivity; hypersensitivity reactions occurred in 4% of trial patients, and injection-site reactions in 25% vs 14% on placebo [2].

Picking one: the short version

For a premenopausal woman whose only complaint is low desire meeting the label definition, and who does not have uncontrolled hypertension or known cardiovascular disease, bremelanotide is the one of the two with an approved indication and trial evidence [1][4].

For an HIV-infected adult with lipodystrophy and excess abdominal fat, tesamorelin is the one with the approved indication and trial evidence; low sexual desire is not a labeled use of it [2].

PT-141 bought as a peptide is not Vyleesi

Vyleesi is the approved bremelanotide product, a 1.75 mg autoinjector [1]. Products sold as 'PT-141' for research or compounding are not Vyleesi and are not FDA-approved drugs; compounded drugs are not reviewed by FDA for safety, effectiveness or quality before marketing [8][1]. Bremelanotide does not appear on FDA's list of bulk substances that may present significant safety risks when compounded [9]. Tesamorelin is not on that list either, and it is not one of the six peptides named in HHS's October 2026 draft enforcement-discretion policy [9][10].