Is selepressin FDA-approved, and what does the research show?

What is selepressin?

Selepressin is an investigational peptide drug built as a modified copy of vasopressin, a hormone that narrows blood vessels ². Chemists call such a copy an analog. Its designers wanted a drug that was "potent, selective, and short-acting" at one of vasopressin's receptors, the V1a receptor ². A receptor is the docking site on a cell through which a hormone or a drug acts.

Ferring Pharmaceuticals sponsored the three registered trials cited here, the two earliest under the code name FE 202158 ⁴, ⁵, ⁶. All three enrolled adults in septic shock ⁴, ⁵, ⁶. Selepressin is not a wellness, weight or performance product.

Sepsis is the body's disordered response to an infection, severe enough to make organs fail and to threaten life ¹. Septic shock is its most severe form: blood vessels widen and leak, blood pressure falls, and tissues run short of oxygen ¹. Treatment includes antibiotics, fluids into a vein, organ support and vasopressors, drugs that raise blood pressure by tightening blood vessels ¹. "Even with prompt care," the trial's paper says, "many patients develop multiple organ failure and death" ¹.

Is selepressin FDA-approved?

Selepressin is not FDA-approved: Drugs@FDA lists no approved selepressin product as of November 9, 2026 ³. It is an investigational drug, and ClinicalTrials.gov lists the largest trial cited here as "Terminated," with the reason "Terminated due to futility" (last update posted April 6, 2021) ⁴. With no approved product there is no FDA label, the document that carries a drug's approved uses and FDA-reviewed warnings ³.

On November 10, 2026, ClinicalTrials.gov listed three trials with selepressin or FE 202158 as the intervention, the treatment under test ⁴, ⁵, ⁶. Two are listed as phase 2 trials with the status "Completed," last update posted September 25, 2017, for one and March 23, 2017, for the other ⁵, ⁶. The third is listed as a phase 2 and phase 3 trial with the status "Terminated," last update posted April 6, 2021 ⁴.

Phase 2 trials are early tests in patients; phase 3 trials are the large, late-stage trials run to support approval. The third trial joined the two stages in one design, and its design paper's title calls it "an Adaptive Phase 2b/3 Clinical Trial" ⁷. Phase 2b is a label for the later part of phase 2 testing.

That trial ran "under a Special Protocol Assessment agreement with the US Food and Drug Administration," its paper says ¹. A Special Protocol Assessment is a process in which FDA reviews a trial's design in advance and agrees it with the sponsor. The agreement concerned the trial, and it was not an approval of the drug ⁷, ³.

Outside a clinical trial, no source cited here shows a way for a patient to receive selepressin. None of the sources cited here describes an expanded access program, the supply of an unapproved drug to a patient outside a trial ⁴, ⁵, ⁶. Pharmacy compounding, in which a pharmacy prepares a medicine for one patient, is not shown as a route in these sources either. FDA's list of bulk drug substances nominated for compounding under section 503A of the drug law, updated May 14, 2026, does not name selepressin ⁸. The matching list under section 503B, for outsourcing facilities, updated March 21, 2025, does not name it either ⁹.

Vasopressin itself is a different drug. The selepressin trial's 2019 paper says FDA had recently "approved 2 noncatecholaminergic vasopressors for use in septic or vasodilatory shock: vasopressin and angiotensin II" ¹. Noncatecholaminergic means they do not belong to the catecholamines, the chemical family of norepinephrine, the recommended first vasopressor in septic shock ¹. That approval does not cover selepressin ³. Vasopressin has its own page in this library.

See the FDA status of every peptide, updated weekly.

How does selepressin work?

Selepressin is an agonist of the vasopressin V1a receptor, which means it switches that receptor on ¹, ². Vasopressin, the trial's paper explains, "induces vasoconstriction via V1 receptor stimulation in vascular smooth muscle"; in plain words, it makes the muscle in vessel walls tighten ¹. But vasopressin "also stimulates V1b and V2 receptors," and the paper calls the effects that follow "not all beneficial in septic shock" ¹. They include "salt and water retention" and "increased procoagulant factors," substances that promote clotting ¹.

The evidence that selepressin is selective comes from the laboratory. Shown in cells: in assays of human receptors, selepressin favored V1a over the V1b, V2 and oxytocin receptors by ratios of 142, 1,107 and 440 ². Vasopressin, tested the same way, showed a "lack of selectivity" ². Studied in animals: in rats, selepressin narrowed blood vessels and, unlike vasopressin, showed no antidiuretic activity at the dose tested ². Antidiuretic activity is the kidney effect that holds back urine.

The reason to look beyond norepinephrine is given in the 2019 paper ¹. Norepinephrine "is not always effective at restoring blood pressure and can cause myocardial and peripheral ischemia," reduced blood supply to the heart muscle and the limbs ¹. Selepressin's proposed advantage was to counter the widening and leaking of blood vessels and the tissue swelling, called edema, "without V1b- or V2-mediated effects" ¹. That was a hypothesis when the large trial began ¹.

What does the research show?

Studied in people: SEPSIS-ACT, a randomized, placebo-controlled trial, 868 adults with septic shock who needed norepinephrine, days alive and free of ventilator and vasopressors within 30 days ¹. A ventilator is a breathing machine. The trial was blinded: neither the clinical team nor the investigators knew who received selepressin and who received placebo, a salt-water infusion ¹, ⁴.

The trial ran from July 2015 to August 2017 at hospitals in Belgium, Denmark, France, the Netherlands and the United States ¹. Of the 868 patients randomized, 828 received study drug: 562 received one of three selepressin dosing regimens and 266 received placebo ¹. Any patient who died within 30 days was counted as having zero free days ¹.

The design was adaptive, meaning preset rules used the accumulating results to steer the trial ¹, ⁷. Part 1 compared the dosing regimens ¹. Part 2, which could have taken the trial to 1,800 patients, would open only if one regimen looked likely enough to succeed ¹.

In the paper's words, "no study group triggered transition to part 2. Therefore, based on recommendation from the DSMB, the TSC stopped the trial for futility at the end of part 1" ¹. The DSMB is the independent data and safety monitoring board, and the TSC is the trial steering committee ¹.

The paper reports that the primary end point "of ventilator- and vasopressor-free days did not differ significantly between the combined selepressin and placebo groups (mean, 15.0 vs 14.5 days; difference, 0.6 days [95% CI, −1.3 to 2.4]; P = .30)" ¹. The first figure of the pair is selepressin's and the second is placebo's. A 95% confidence interval, or CI, is the range in which the true difference plausibly lies, and here it includes zero. The P value estimates how readily chance alone could produce a gap of this size.

For its three key secondary outcomes the paper reports "no significant differences" ¹. Death within 90 days came to 40.6% in the selepressin groups against 39.4% on placebo ¹. Days free of kidney replacement therapy, such as dialysis, were 18.5 against 18.2, and days out of intensive care were 12.6 against 12.2 ¹, ⁴.

The authors conclude that selepressin, "compared with placebo, did not result in improvement in vasopressor- and ventilator-free days within 30 days" ¹. Their discussion says "there was no evidence that selepressin offered any benefit" on the primary end point "or other patient-centered outcomes" ¹.

The paper also reports how the shock was managed during the infusion, and it says findings on its other secondary end points "should be interpreted as exploratory" ¹. Over the first six hours, mean arterial pressure, the pressure in the arteries averaged over a heartbeat, was 74 mm Hg with selepressin against 70 with placebo ¹. The paper gives the change in norepinephrine need as "a 41% reduction vs 8% increase from baseline," selepressin first and placebo second ¹. In the first 24 hours the selepressin group passed more urine and retained less fluid, "but the groups were similar thereafter" ¹.

The paper also sets selepressin beside the two approved drugs. Selepressin, vasopressin and angiotensin II, it says, "all appear to have norepinephrine-sparing effects without an increase in adverse events but also without evidence that their use improves patient-centered outcomes compared with a catecholamine-based strategy" ¹. It adds that "none of these 3 agents have been compared with each other" ¹.

The 2019 paper says that in "a phase 2a trial in patients with septic shock, selepressin reduced norepinephrine requirements, increased the proportion of patients not receiving mechanical ventilation, and appeared to speed resolution of shock" ¹. That sentence gives no trial size, no placebo figures and no registry number. Phase 2a is a label for the earliest phase 2 testing in patients. Those findings, the paper says, led to its larger trial ¹. The phase 2a trial's paper reports it as NCT01000649, the 53-patient trial below ¹⁰.

Studied in people: a randomized, double-blind, placebo-controlled phase 2 trial, 53 adults with early septic shock, the proportion holding a target blood pressure without open-label norepinephrine ⁵. Open-label norepinephrine was norepinephrine given openly alongside the blinded study infusion. Patients received one of three ascending doses of selepressin or placebo for up to seven days ⁵.

At 24 hours the registry gives 68.8% for the middle-dose group, 10.0% for the lowest-dose group and 20.0% for placebo ⁵. Those groups had 19, 10 and 21 patients dosed ⁵. By day 7 the figures were 80.0%, 62.5% and 100.0% ⁵. The two patients assigned to the highest dose "were both discontinued within 5 hours after start of infusion," and that group was not analyzed ⁵.

Studied in people: an open-label phase 2 feasibility trial, 31 adults in early septic shock enrolled and 30 dosed, the percentage holding the target pressure without norepinephrine ⁶. Open-label means everyone knew the drug was being given, and the trial had no placebo group ⁶. A feasibility trial tests whether a treatment plan is workable before a larger trial is run. Across its four infusion regimens, in groups of 5 to 13 patients, that percentage ranged from 42.9% to 80.0% at 24 hours ⁶. The large trial's doses were chosen from this study ¹.

The 2019 paper ends: "Further research would be needed to evaluate the potential role of selepressin for other patient-centered outcomes in septic shock" ¹. None of the sources cited here studies selepressin for weight, wellness or athletic performance ¹, ⁷, ⁴, ⁵, ⁶, ², ¹⁰.

What are the side effects?

What the sources document was seen in adults in septic shock, among whom deaths were common in every group ¹, ⁴. By day 180, 241 of the 562 patients given selepressin and 116 of the 266 given placebo had died ⁴.

In SEPSIS-ACT, the paper says, "Event rates were similar in both groups" ¹. Cardiac arrhythmias, or abnormal heart rhythms, occurred in 27.9% of patients in the selepressin groups against 25.2% on placebo ¹. Cardiac ischemia occurred in 6.6% against 5.6% ¹. Mesenteric ischemia, reduced blood supply to the gut, occurred in 3.2% against 2.6%, and peripheral ischemia in 2.3% of each ¹.

The paper's adverse-event table adds stroke and other cerebrovascular events at 2.3% against 1.5% ¹. Serious adverse events over the trial's 30-day period stood at 51.2% with selepressin against 53.4% with placebo ¹. A serious adverse event is one that is fatal or life-threatening, or that needs or prolongs hospital care. Events that led to stopping the study drug stood at 7.3% with selepressin against 4.5% with placebo ¹.

A table note says, "The study was not powered to test for differences in adverse event rates" ¹. In plain words, it was too small to tell such gaps from chance.

The registry counts events during the infusion or within 12 hours of its end ⁴. On that count a serious adverse event occurred in 179 of 562 patients given selepressin and 85 of 266 given placebo ⁴. The most frequent serious event it lists is multiple organ dysfunction syndrome, the failure of two or more organ systems, in 39 of 562 against 24 of 266 ⁴. Septic shock follows, in 30 against 15 ⁴. Cardiac arrest is listed in 11 against 3, intestinal ischemia in 7 against 3, and peripheral ischemia in 7 against 1 ⁴.

One organ score differed. A score of blood clotting function was "significantly higher in the selepressin group" on days 3 and 7 in intensive care, and a higher score is a worse one ¹. The paper gives means of 1.73 against 1.50 on day 3 and 1.53 against 1.30 on day 7 ¹. New clotting abnormalities in the first week were recorded in 62.3% with selepressin against 53.3% with placebo, with "no significant differences by day 30" ¹.

In the 53-patient phase 2 trial, the registry lists a serious adverse event in 6 of the 21 patients on placebo ⁵. In the two lower-dose groups it lists one in 2 of 10 and 2 of 19 ⁵. Both patients in the highest-dose group left the trial because of an adverse event ⁵. The serious events listed for them are a cardio-respiratory arrest and myocardial ischemia ⁵. In the open-label trial, 10 of the 30 patients dosed had a serious adverse event, with no comparison group ⁶.

The large trial did not enroll patients with "Known/suspected acute mesenteric ischaemia" or with a suspected acute coronary syndrome such as a heart attack ⁴. It also did not enroll patients "Known to be pregnant" ⁴.

In sport

WADA, the World Anti-Doping Agency, does not name selepressin on its 2026 Prohibited List ¹¹. Section S5 names desmopressin, which its FDA label calls "a synthetic vasopressin analog" ¹², and closes with "Probenecid and other substances with a similar chemical structure or similar biological effect(s)" ¹¹. The list's section S0 covers non-approved substances: "Any pharmacological substance which is not addressed by any of the subsequent sections of the List and with no current approval by any governmental regulatory health authority for human therapeutic use (e.g. drugs under pre-clinical or clinical development or discontinued, designer drugs, substances approved only for veterinary use) is prohibited at all times" ¹¹. FDA is the only regulator whose records were read, and Drugs@FDA lists no approved selepressin product ³. Whether either section covers selepressin is for anti-doping authorities to decide.

In the trials selepressin was given by infusion into a vein ¹, ⁵. Rule M2.2 of the list prohibits "Intravenous infusions and/or injections of more than a total of 100 mL per 12-hour period except for those legitimately received in the course of hospital treatments, surgical procedures or clinical diagnostic investigations" ¹¹.

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JumpstartMD does not prescribe selepressin. Our peptide library covers it so you have the facts on its FDA status and the evidence, current as of November 10, 2026.

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Compounded medications are not FDA-approved, and FDA does not review their safety, effectiveness, or quality before they are marketed. A licensed clinician decides after an evaluation whether a peptide is appropriate for you, and not every patient will qualify.