Is pentapeptide-18 FDA-approved, and what does the research show?

What is pentapeptide-18?

Pentapeptide-18 is a synthetic peptide, a short chain of amino acids, the building blocks of proteins ¹,². Its chain has five: tyrosine, D-alanine, glycine, phenylalanine and leucine ². D-alanine is the mirror-image form of the amino acid alanine. Lipotec, a company in Barcelona, Spain, makes it under the trade name Leuphasyl ¹,². It goes into creams aimed at expression wrinkles, the lines that repeated movements of the facial muscles leave in the skin ¹,².

It is a cosmetic ingredient, and all three studies of products holding the peptide cited here applied them to the skin, as an emulsion or a cream ¹,²,⁵. It is not a peptide for weight loss or athletic performance; no source cited here studied it for either ¹,⁶,²,⁵.

Is pentapeptide-18 FDA-approved?

No, and as a cosmetic ingredient it does not need to be. "Under the law, cosmetic products and ingredients do not need FDA premarket approval, with the exception of color additives," says FDA's page on its authority over cosmetics, current as of November 18, 2025 ⁴. Nor is pentapeptide-18 approved as a drug: Drugs@FDA, FDA's database of approved drug products, lists no pentapeptide-18 or Leuphasyl product as of November 9, 2026 ³.

Safety is the job of whoever makes or sells the cream ⁴. "Companies and individuals who manufacture or market cosmetics have a legal responsibility to ensure the safety of their products," FDA writes ⁴. It adds: "Neither the law nor FDA regulations require specific tests to demonstrate the safety of individual products or ingredients" ⁴. A cream containing pentapeptide-18 that is sold as a cosmetic can therefore go on sale without FDA's approval beforehand ⁴.

The Modernization of Cosmetics Regulation Act of 2022, called MoCRA, gave FDA the power to order a recall, under conditions FDA sets out ⁷. In FDA's words: "If the agency determines that there is a reasonable probability that a cosmetic is adulterated or misbranded and the use of or exposure to the cosmetic will cause serious adverse health consequences or death, FDA has the authority to order a mandatory recall if the responsible person refuses to do so voluntarily" ⁷. Adulteration concerns what a product is made of, and misbranding its labeling or packaging ⁴. The responsible person is the manufacturer, packer or distributor named on the label ⁷. That person "is required to ensure and maintain records supporting adequate safety substantiation of their cosmetic products" ⁷.

What a product is sold to do matters too. FDA says a product "intended for a therapeutic use, such as treating or preventing disease, or to affect the structure or function of the body" is a drug, or in some cases a medical device, "even if it affects the appearance" ⁴. FDA's page on anti-aging products draws the line: a product intended "to remove wrinkles or increase the skin's production of collagen" is "a drug or a medical device" ⁸.

See the FDA status of every peptide, updated weekly.

How does pentapeptide-18 work?

The mechanism is proposed; no study cited here tested it ¹,²,⁵. Three papers describe the peptide as acting like enkephalins, and one of the three labels Leuphasyl "pentapeptid-3" ¹,²,⁵. Enkephalins are peptides the body makes itself.

The 2014 paper says it would attach to the enkephalin receptor on nerve cells and lower the release of acetylcholine, the chemical signal that tells a muscle to contract ¹. The 2024 night-cream paper says it resembles the enkephalin pathway in reducing acetylcholine release ². The same group's eye-cream paper says the peptide binds enkephalin receptors, closes calcium channels and reduces acetylcholine release ⁵. The 2014 paper says a weaker signal would mean a more relaxed muscle and softer expression lines ¹. The 2014 paper and the night-cream paper take this account from a review or from the maker's own document, not from experiments of their own ¹,².

A 2026 study examined the molecule itself ⁶. It calculated the peptide's structure and checked the result with spectroscopy, which reads a molecule from the light it absorbs and scatters ⁶. Computer simulations then modeled how the peptide binds molecular targets linked to skin aging ⁶. Its abstract describes no test in cells, animals or people ⁶.

None of the studies cited here measured whether the peptide in a cream reaches the muscle beneath the skin ¹,²,⁵. The authors of a 2026 paper wrote, as a general statement and not as a finding on pentapeptide-18, that "topical BTX-A mimetic peptides cannot penetrate deeply enough to impact muscle contraction similarly to intramuscular injections" ⁹. BTX-A is botulinum toxin type A, the injected wrinkle treatment ⁹. Their paper tested creams used after botulinum toxin injections, and the peptides it lists in those creams are Munapsys, X50 Myocept, Syn-Ake and Argireline ⁹. It names pentapeptide-18 once, in its introduction's list of synthetic cosmetic peptides: "Argireline (Acetyl Hexapeptide-8), Snap-8 (Acetyl Octapeptide-3), Leuphasyl (Pentapeptide-18), and Vialox (Pentapeptide-3)" ⁹.

What does the research show?

Studied in people: three small studies of products holding the peptide are cited here, one with no comparison group and two that set retinol-and-peptide creams against their own base creams ¹,²,⁵. None tested the peptide alone against a placebo, a cream with no active ingredient ¹,²,⁵.

In the first, published in 2014, researchers made three Leuphasyl emulsions, at 0.5, 1 and 2 percent ¹. Twenty volunteers aged 30 or older applied them daily for two months, over the muscles between the eyebrows and around the eyes ¹. Wrinkle size was read each week from two-dimensional images ¹.

The paper labels Leuphasyl "pentapeptid-3" ¹. Four other papers cited here give Leuphasyl as pentapeptide-18 ⁶,²,⁹,⁵. One of the four gives pentapeptide-3 as Vialox, another trade name ⁹.

Only the 2 percent emulsion brought what the authors call "important ameliorations" ¹. For that emulsion, between the eyebrows and around the eyes (the periorbital zone), the paper reports: "The size of the wrinkles trajectory was smaller with the following average: 34.7% for frontal region (inter eye-brows zone); 28.4% for periorbital zone" ¹. No volunteer's wrinkles disappeared completely ¹.

The paper says it compared the wrinkles' change over time, and gives no starting sizes ¹. It describes no placebo or untreated group and gives no statistical test ¹. It does not say how the 20 were divided among the three emulsions, or how many finished ¹.

The authors judged the peptide "evidently inferior to botulinum toxin injections" ¹. They also wrote that published results for Argireline were "quite superior" ¹. They declare no conflict of interest, and the paper names no funder ¹.

The second paper is a formulation study from Poznań, Poland ². Its authors loaded retinol, a vitamin A compound, and pentapeptide-18 into solid lipid nanoparticles, tiny carriers made of fat ². They mixed the particles into night creams, measured the creams' stability, then tested them on two groups of 20 women for eight weeks ².

Each woman received two creams: one with the loaded particles, and its base cream without them ². The anti-aging particle cream held 10 percent of the particle dispersion and the anti-acne cream 5 percent ². The base cream's ingredient list carries neither retinol nor the peptide ².

The anti-aging group was aged 30 to 65 and had signs of skin aging ². With the particle cream, the number of wrinkles fell 29 percent on the forehead and 18 percent near the eyes ². With the base cream it fell 6 and 9 percent ². Maximum wrinkle depth fell 8 percent on the forehead and 3 percent near the eyes with the particle cream, and did not change significantly with the base ². Each figure is a change from the study's start to week 8 ².

The anti-acne group was aged 18 to 65 and had blemishes and inflamed skin ². With the particle cream, sebum, the skin's oil, was 19 percent lower on the forehead and 14 percent lower on the cheek at week 8 ². With the base cream the falls were 6 percent on the forehead and 9 percent on the cheek ².

The particle creams differ from their bases by retinol, the peptide and the carrier together, so no result is the peptide's alone ². The authors themselves credit the "additive effect of retinol and oligopeptide" ². The paper does not describe randomization, the assigning of treatments by chance, or blinding, the hiding of which cream is which ². Nor does it say how each woman divided the two creams, or how many finished ². The creams were "produced by Dottore Polska Sp. z o.o.," which employed two of the four authors, and the work was "partially funded by the Ministry of Science and Higher Education" ².

A companion paper from the same group tested an eye cream holding retinol and pentapeptide-18 particles against its base in 20 women for eight weeks ⁵. It assessed the number, depth and length of wrinkles in the eye area, from images of the skin's surface ⁵.

None of the three studies of products holding the peptide ran longer than about two months ¹,²,⁵. No study cited here compared pentapeptide-18 with botulinum toxin, or with another peptide, in the same people ¹,²,⁵. PubMed and Europe PMC's full-text index, searched on November 10, 2026, returned further papers that name the peptide, and those are not among the studies cited here.

What are the side effects?

The studies cited here say little about them. The 2014 emulsion study, which had no placebo group, describes no safety measurements and reports no adverse events ¹. Even so, its conclusion calls Leuphasyl, which the paper labels "pentapeptid-3," "absolutely free from side effects" ¹. In the Polish cream study, "Any adverse effects were to be reported to the investigator" ². Its results list no adverse events and do not say whether any were reported ².

That study's instruments did record one change in the skin barrier ². Transepidermal water loss is the rate at which water escapes through the skin ². With the anti-aging particle cream it rose 7 percent on the cheek and 3 percent on the forehead at week 8 ². With the base cream it was 8 percent lower on the cheek at week 8, and the paper calls the forehead change not significant ².

The authors attribute the rise to the cream's retinol ². The same study, whose creams held retinol, named pregnancy and breastfeeding as the main contraindications to taking part ². Of adverse effects among its volunteers, the companion eye-cream paper says only that "Any adverse effects were to be reported to the principal investigator" ⁵.

The 2026 computer study's abstract calls the peptide a potential "safe, effective, and non-invasive candidate" ⁶. That abstract describes calculations and predictions, and no test in people ⁶.

The Cosmetic Ingredient Review publishes the findings of its Expert Panel for Cosmetic Ingredient Safety ¹⁰. Its Quick Reference Table, as updated in December 2025, lists no entry for pentapeptide-18 or Leuphasyl ¹⁰.

In sport

The World Anti-Doping Agency's 2026 Prohibited List does not name pentapeptide-18 or Leuphasyl ¹¹. Nor does it name enkephalins, the natural peptides the ingredient is said to imitate ¹¹,².

What JumpstartMD offers

JumpstartMD does not prescribe pentapeptide-18. 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.