RECONNECT Trial: A Plain-English Overview of What It Established

At a glance

Detail	Value
Trial name	RECONNECT (Study 301 / Study 302, pooled)
N	1,247 premenopausal women with HSDD
Intervention	Bremelanotide 1.75 mg subcutaneous, self-administered as needed
Comparator	Matching placebo subcutaneous injection
Duration	24 weeks (double-blind)
Primary endpoints	Change in desire domain of FSFI; change in feeling bothered on FSDS-DAO Item 13
Key result	Statistically significant improvement on both co-primary endpoints vs. placebo
Reg. outcome	Supported FDA approval of Vyleesi (June 2019)

What question did this trial ask?

Before RECONNECT, the only FDA-approved drug for HSDD in premenopausal women was flibanserin (Addyi), a daily oral pill with alcohol restrictions and modest efficacy. The clinical question was straightforward: can an on-demand, self-injected melanocortin-4 receptor agonist increase sexual desire and reduce the distress that accompanies its absence, without requiring daily dosing?

Bremelanotide acts centrally on MC4R pathways involved in sexual arousal. Unlike flibanserin, which modulates serotonin and dopamine over weeks of daily use, bremelanotide was designed for use roughly 45 minutes before anticipated sexual activity. The RECONNECT program pooled two identically designed Phase 3 studies (Study 301 and Study 302) to answer this question with enough statistical power to satisfy the FDA.

Who was enrolled, and who was excluded?

Participants were premenopausal women aged 18 and older who met DSM-IV-TR criteria for HSDD (generalized acquired type). They had to be in a stable, sexually active relationship for at least six months and had to report distress about low desire on validated screening instruments.

Key exclusion criteria narrowed the population considerably:

• Women with arousal disorder, sexual pain disorders, or depression as the primary driver of low desire
• Uncontrolled hypertension (systolic >140 mmHg or diastolic >90 mmHg)
• Active cardiovascular disease
• Use of antidepressants, antipsychotics, or other medications known to impair sexual function
• Any other concurrent sexual dysfunction medication

RECONNECT enrollment filter: who the trial actually studied

Understanding these filters matters. The trial population was relatively narrow: premenopausal, otherwise healthy, not on SSRIs, in a stable relationship, with generalized acquired HSDD only. This is a real but specific clinical scenario. Women whose low desire stems from medication side effects, relationship conflict, depression, menopause, or mixed arousal-desire complaints were not represented.

What did participants actually do?

After a four-week screening period (which included a placebo run-in to exclude high placebo responders), eligible women were randomized 1:1 to bremelanotide 1.75 mg or placebo. Each participant received an autoinjector pen for subcutaneous abdominal injection, to be used approximately 45 minutes before anticipated sexual activity. Dosing was limited to no more than once per 24-hour period and no more than eight doses per month, per protocol.

The treatment period lasted 24 weeks. Participants recorded sexual events and symptoms in an electronic diary. Clinical visits occurred at baseline, weeks 4, 8, 12, and 24. At each visit, clinicians administered the co-primary outcome instruments.

Both Study 301 and Study 302 used identical protocols, randomization ratios, and endpoints, which allowed the FDA to evaluate pooled data from the full 1,247-patient population.

What was measured?

The trial used two co-primary endpoints, both of which had to reach statistical significance:

1. FSFI desire domain score (Female Sexual Function Index, desire subscale): a two-item patient-reported measure scored 1.2 to 6.0, where higher is better.
2. FSDS-DAO Item 13 (Female Sexual Distress Scale, Desire/Arousal/Orgasm, Item 13: "How often did you feel bothered by low sexual desire?"): scored 0 to 4, where lower is better.

Secondary endpoints included the full FSFI total score, the number of satisfying sexual events (SSEs), and other FSDS-DAO items.

What did the trial find?

Co-primary endpoints (24 weeks, pooled)

Both co-primary endpoints were met. The improvements were statistically significant in the pooled RECONNECT analysis.

What those numbers mean in practice

The FSFI desire domain runs from 1.2 to 6.0. A 0.3-point treatment difference on a roughly 5-point scale is small in absolute terms. The FSDS-DAO Item 13 improvement of 0.3 points on a 0 to 4 scale is similarly modest.

However, responder analyses tell a somewhat more encouraging story. About 35% of bremelanotide-treated women reported a "meaningful" improvement in desire (defined as a ≥0.9-point FSFI desire gain or a ≥1-point FSDS-DAO Item 13 drop) compared to roughly 23% on placebo. That 12-percentage-point gap means the number needed to treat (NNT) sits around 8 to 9. For a subjective, quality-of-life condition, this is in the same range as many psychiatric medications.

Secondary endpoints

Satisfying sexual events increased numerically in both groups but did not consistently reach statistical significance across both studies. The full FSFI total score improved more with bremelanotide than placebo, but the desire domain carried most of that difference.

Safety: the nausea problem

The headline safety finding was nausea.

Roughly four in ten women experienced nausea, though it typically decreased with repeated dosing. Still, 14% of the bremelanotide group stopped treatment because of side effects, more than triple the placebo rate. The FDA label carries a specific warning about nausea and recommends antiemetic pretreatment if needed.

Bremelanotide also caused transient blood pressure increases (mean systolic rise of approximately 3 mmHg peaking about 2 to 3 hours post-dose) and transient facial hyperpigmentation in some women with darker skin tones. The blood pressure effect led to a contraindication in women with uncontrolled hypertension or known cardiovascular disease.

Limitations the authors and reviewers acknowledged

Several limitations deserve attention when interpreting RECONNECT:

Narrow population. The exclusion of women on antidepressants, women with comorbid depression, and postmenopausal women limits generalizability. A large share of real-world HSDD patients take SSRIs or SNRIs, and those women were not studied here.

Placebo run-in may inflate effect sizes. By removing high placebo responders before randomization, the trial may understate the placebo response that would occur in routine practice.

Subjective endpoints with no objective anchor. Both co-primary endpoints are patient-reported. There is no biomarker or physiological measure of desire. This is not unique to RECONNECT; it is inherent to HSDD research, but it means the results rest entirely on self-report scales.

Short duration. Twenty-four weeks is reasonable for a regulatory trial, but HSDD is typically a chronic condition. The open-label extension provided some longer-term data, but the controlled comparison ends at six months.

High nausea rate and its interaction with blinding. When 40% of the active group experiences nausea and 1% of placebo does, functional unblinding is almost certain. Participants who became nauseated likely knew they were on the real drug, which could influence subjective outcome reporting in either direction.

SSE endpoint inconsistency. The satisfying sexual events endpoint, often considered the most face-valid outcome, did not consistently reach significance across both studies, which raises questions about whether the desire improvement translated into behavioral change.

How did the FDA weigh this evidence?

The FDA approved bremelanotide (Vyleesi) in June 2019 based primarily on the RECONNECT data. The advisory committee vote was not unanimous. Committee members debated whether the effect size was clinically meaningful and whether the nausea burden was acceptable. The approval came with a limited indication (premenopausal women with acquired, generalized HSDD) and labeling that emphasized it is not for enhancing sexual performance in women without HSDD.

The ISSWSH (International Society for the Study of Women's Sexual Health) guidelines recognize bremelanotide as a treatment option for HSDD, positioning it alongside flibanserin. ISSWSH clinical practice statements note that on-demand dosing may appeal to women who prefer not to take a daily medication but that nausea management is an important counseling point.

What this means for clinical practice today

Bremelanotide fills a specific niche. It is the only FDA-approved on-demand pharmacotherapy for HSDD in premenopausal women. For a woman who has tried behavioral and psychological approaches, does not want daily medication, is not on interacting drugs, and tolerates subcutaneous injection, it is a reasonable option.

The practical barriers are real. The injection route is less convenient than an oral pill. Nausea affects a substantial minority. Insurance coverage varies widely, and the out-of-pocket cost without coverage can exceed $900 per month. The prescribing information recommends no more than one dose per 24 hours and no more than eight per month.

Clinicians should set expectations clearly: RECONNECT showed a statistically significant but modest average improvement. Some women respond well, many respond partially, and some do not respond at all. The NNT of roughly 8 to 9 means that for every eight or nine women who try it, about one will have a meaningful response beyond what placebo would provide.

Frequently asked questions

›What is the RECONNECT trial?

RECONNECT was the key Phase 3 clinical program (two pooled studies, N=1,247) that tested bremelanotide 1.75 mg subcutaneous injection against placebo in premenopausal women with hypoactive sexual desire disorder. It provided the primary efficacy and safety data for the FDA approval of Vyleesi in 2019.

›How effective was bremelanotide in the RECONNECT trial?

Bremelanotide produced statistically significant improvements on both co-primary endpoints: sexual desire (FSFI desire domain) and distress about low desire (FSDS-DAO Item 13). The average treatment differences were modest (about 0.3 points on each scale), but responder analyses showed roughly 35% of treated women had a meaningful response compared to 23% on placebo.

›What were the main side effects of bremelanotide?

Nausea was the most common side effect, affecting about 40% of women on bremelanotide versus 1% on placebo. Flushing (20%), injection site reactions (13%), and headache (11%) were also reported. About 14% of the bremelanotide group discontinued due to adverse events.

›Is Vyleesi a daily medication?

No. Vyleesi is used on demand, self-injected subcutaneously approximately 45 minutes before anticipated sexual activity. The FDA label limits use to one dose per day and no more than eight doses per month.

›Who was eligible for the RECONNECT trial?

Premenopausal women aged 18 and older with generalized acquired HSDD who were in stable sexual relationships. Women with depression-driven low desire, those on antidepressants, women with uncontrolled hypertension, and those with other primary sexual dysfunction diagnoses were excluded.

›Does bremelanotide increase sexual events?

The satisfying sexual events endpoint did not consistently reach statistical significance across both RECONNECT studies. Desire and distress improved, but the translation to more frequent satisfying encounters was not reliably demonstrated.

›How does bremelanotide compare to flibanserin?

They work by different mechanisms (melanocortin vs. serotonin/dopamine modulation), have different dosing (on-demand injection vs. daily oral pill), and different side effect profiles (nausea vs. sedation and alcohol restriction). No head-to-head trial has directly compared them. Both have modest effect sizes.

›Can postmenopausal women use Vyleesi?

The FDA approval is limited to premenopausal women. Postmenopausal women were not enrolled in RECONNECT, so efficacy and safety in that population have not been established in a key trial.

›Does nausea from bremelanotide improve over time?

Trial data suggest that nausea severity and frequency tend to decrease with repeated dosing, though it does not resolve completely for all users. The FDA label suggests considering antiemetic pretreatment if nausea is bothersome.

›Is Vyleesi covered by insurance?

Coverage varies by plan and is often limited. Without insurance, the out-of-pocket cost can exceed $900 per month. Some manufacturer support programs exist, but access remains a practical barrier for many patients.

References

• Kingsberg SA, Clayton AH, Portman D, et al. Bremelanotide for the Treatment of Hypoactive Sexual Desire Disorder: Two Randomized Phase 3 Trials. Obstet Gynecol. 2019;134(5):899-908. PubMed
• Vyleesi (bremelanotide) prescribing information. U.S. Food and Drug Administration. 2019. FDA Label
• Parish SJ, Simon JA, Davis SR, et al. International Society for the Study of Women's Sexual Health Clinical Practice Guideline for the Use of Systemic Testosterone for Hypoactive Sexual Desire Disorder in Women. J Sex Med. 2021;18(5):849-867. PubMed
• Jaspers L, Feys F, Bramer WM, et al. Efficacy and Safety of Flibanserin for the Treatment of Hypoactive Sexual Desire Disorder in Women: A Systematic Review and Meta-analysis. JAMA Intern Med. 2016;176(4):453-462. PubMed
• Clayton AH, Althof SE, Kingsberg S, et al. Bremelanotide for female sexual dysfunctions in premenopausal women: a randomized, placebo-controlled dose-finding trial. Womens Health (Lond). 2016;12(3):325-337. PubMed