What are semax, selank, KPV and DSIP?

What they are

Semax, selank, KPV and DSIP are short peptides: chains of three to nine amino acids, the building blocks of proteins. None is FDA-approved for any use. Sellers promote semax for focus and anxiety, selank for focus, KPV for inflammation and DSIP for sleep.^1,2,3,11,30

Semax starts with four amino acids from ACTH (adrenocorticotropic hormone), which prompts the adrenal glands to make the stress hormone cortisol. Moscow’s Institute of Molecular Genetics added three more, which FDA staff say is thought to slow its breakdown. The ACTH fragment that semax is based on lacks the hormone’s effects on the adrenal glands and on skin pigment, they note. It is registered in Russia as nose drops.^1,6,7,8

Selank was co-developed at the same institute. It is built from tuftsin, an immune-stimulating chain of four amino acids cut from an antibody protein, plus the same three-amino-acid tail as semax. It is registered in Russia as an anti-anxiety drug. A 2021 US review called it a poorly studied Russian drug sold to US consumers as a dietary supplement.^{8,9,1,7,10,12,20}

KPV is lysine, proline and valine, the last three amino acids of alpha-MSH (alpha-melanocyte-stimulating hormone). That hormone raises skin pigment and damps inflammation, and researchers have studied KPV as a way to keep the second effect without the first. In a 1989 study, a form of the fragment reduced ear swelling in mice; FDA staff say that form was chemically modified (acetylated).^2,13,14

DSIP, short for delta sleep-inducing peptide, has nine amino acids; its official international name is emideltide. Researchers isolated it from rabbits in 1977 and named it for the slow delta brain waves of deep sleep. A 2022 review lists a Russian DSIP product among drugs registered in Russia, for stress and alcohol addiction; the FDA describes it as DSIP mixed with glycine, an amino acid. The FDA found emideltide itself registered in no country it searched.^15,5,3,7

How they work

In rodents, semax protected brain tissue after its blood supply was cut, eased pain and had anti-anxiety-like and antidepressant-like effects. FDA staff describe how it works as poorly understood.¹

In lab tests on brain cell membranes, selank changed how GABA, a chemical messenger that quiets nerve activity, binds to its receptors. Benzodiazepine sedatives act on the same receptors.¹⁶

In human gut and immune cells grown in a dish, KPV entered through a transporter called PepT1 and damped inflammatory signals, a 2008 study found. KPV does not seem to act on the receptors that alpha-MSH uses, and the FDA says its target is unknown.^17,2

Studies conflict on whether DSIP deepens sleep, and how it acts is unclear. In animals, naloxone, a drug that blocks opioids, prevented its sleep effects. That points to the body’s opioid system, though DSIP does not appear to bind opioid receptors.^3,44

How they are taken

The FDA reviews each form of a peptide as a separate ingredient: the peptide alone (the free base) or paired with acetate (the acetate salt). The FDA found no study that gave semax or DSIP to people as an injection under the skin, one way both are sold.^1,2,3

What the research in people shows

FDA staff judged the evidence in people insufficient for every semax and DSIP use they assessed in 2026. Most semax and selank studies were run in Russia, and many were published only in Russian.^{1,3,18,19,10,20}

For semax, the FDA assessed reduced blood flow to the brain (cerebral ischemia), including stroke, and folded its use as a “nootropic,” meant to improve thinking, into that review. It set aside four Russian-language studies of this use for lack of full English translations. Two compared stroke patients given semax with similar ones who were not: 30 against 80 in 1997, and 110 people in 2018. Both reported faster recovery. The 1997 study’s English summary does not say how patients were assigned; the full 2018 report says they were randomly assigned, with no placebo.^1,18,42

For migraine and facial nerve pain (trigeminal neuralgia), the FDA found one 1996 study of 37 people given a single nasal dose, with no comparison group. A minority with migraine said their headache stopped, and the rest said it eased. Among people with a related dental nerve pain, most said their pain stopped, but their attacks were no fewer or shorter. Pain did not change in typical trigeminal neuralgia.¹

PubMed, the US index of medical research, lists three trials of selank against or alongside a benzodiazepine sedative in people with anxiety, none against a placebo. Each lists N. F. Myasoedov, of the institute where selank was developed, as an author. Two were open-label, meaning patients and doctors knew who got which drug, and were funded in part by a Russian company, Peptogen.^19,10,20,8

No published study has given KPV to people, the FDA found, and on November 14, 2026, the US trial registry ClinicalTrials.gov listed none. In a 2008 mouse study, KPV in drinking water reduced chemically induced colitis (inflammation of the colon). In a 2017 lab study, KPV crossed donated human skin in measurable amounts only with help from tiny needles or a weak electric current.^2,21,17,22

Studies of DSIP in people began in 1981. In double-blind studies, neither patients nor researchers knew whether DSIP or a placebo was given; in a crossover, each person got both, in random order.^23,3

The three studies in the table that reported clear benefits share one lead author; the two by other teams found little or no benefit. A 1984 study of 7 people with severe insomnia, by another researcher and with no comparison group, reported normal sleep in all but one. The FDA called the insomnia evidence inconclusive and at best preliminary.^{24,25,26,27,28,43,3}

For withdrawal, a 1984 Geneva study gave DSIP into a vein to 107 inpatients withdrawing from alcohol or opiates, with no comparison group, and reported that most improved. In a 1998 study of 7 people withdrawing from opioids, symptoms returned despite repeated injections in all but one, the FDA notes.^29,3

Side effects and risks

For all four, the FDA flags immunogenicity: the chance that the immune system reacts against the peptide. Reactions range from antibodies that cause no symptoms to life-threatening reactions. FDA staff also warn that products sold as semax, KPV or DSIP may contain a different salt or substance than the one prescribed.^1,2,3,4

The FDA’s side effect database held one semax report through December 3, 2025. A consumer who used semax nose drops bought online reported eye pain and burning, a hospital stay, and pain that had not cleared a year later.¹

In rats, semax slowed blood clotting, which the FDA says raises a bleeding concern, especially with drugs that increase bleeding. In mice, it strengthened the stimulant amphetamine’s release of dopamine, a brain chemical tied to reward. FDA staff called this concerning because drugs of abuse typically raise dopamine this way. The FDA found no study of whether semax is habit-forming, no standard animal toxicity studies, and no study of how people absorb or clear it.¹

HHS’s draft says these concerns rest on how semax acts, not on harm seen in people, but FDA staff found that most semax studies did not report side effects. A 1999 Russian study of 73 people with brain damage from a lack of oxygen reported bursts of abnormal brain-wave activity in some after semax. Its authors advised monitoring brain activity during the first dose.^38,1,45

The FDA says it lacks important information on selank’s safety in people. A dry nose was the most prominent side effect in the 2014 trial. In lab tests, selank blocked the effect of diazepam, a benzodiazepine, on GABA binding; in stressed rats, it strengthened diazepam’s anti-anxiety effect.^4,10,16,46

For KPV, the FDA found no safety data at all: no human exposure by any route, and no animal toxicity studies of any kind. Its side effect databases held no KPV reports through December 3, 2025, though pharmacies compounding for individual patients generally do not report side effects to the FDA.²

Insomnia studies of DSIP given into a vein found it well tolerated, the FDA says. In the 1984 withdrawal study, 9 of 107 patients had brief effects such as sweating, headache, nausea or vertigo. Three had serious reactions: two had a drop in blood pressure as the first injection began, and one had repeated 15-minute bouts of discomfort with sweating and nausea. In one of the three, blood pressure kept falling after a second injection. Withdrawal causes similar symptoms, the FDA notes. In a 2009 randomized trial of 24 women under general anesthesia, DSIP raised heart rate.^3,29,44

Because DSIP’s effects in animals appear to run through the opioid system, the FDA says it could lead to addiction, and it found no study testing this. Drugs such as captopril, a blood pressure medicine, could raise DSIP levels by blocking its breakdown, FDA staff add. The FDA found no safety data for injection under the skin, no standard animal toxicity studies of repeated doses and no animal studies of effects on reproduction.³

FDA status

None of the four is FDA-approved or listed in Drugs@FDA, the FDA’s approved-drug database. Section 503A of federal law exempts drugs compounded for individual patients from the requirement for FDA approval, but only if each active ingredient passes one of three tests. It must have an official quality standard (a USP monograph), be part of an approved drug, or be on the 503A bulks list, a short list in FDA regulations. FDA documents say none of the four passes any of them.^{30,1,2,3,31,32}

In a 2020 warning letter, the FDA told a Kentucky compounding pharmacy that its drugs made with DSIP, selank and semax did not qualify for this exemption.³²

All four were once in the FDA’s Category 2, nominated ingredients that raise safety concerns, until their nominations were withdrawn. None of the four is now in any FDA category.^4,33

FDA staff reviewed semax, KPV and DSIP for a July 23-24, 2026 meeting of the Pharmacy Compounding Advisory Committee, a panel of outside experts whose advice is not binding. In May 2026 reviews, staff advised against listing any of the three, in either form, citing poorly characterized ingredients, missing safety data, too little evidence of benefit and existing FDA-approved treatments. HHS says the committee voted in favor of semax and KPV; the FDA has posted no results, including for the vote on DSIP. Selank was on neither that agenda nor the next one.^{1,2,3,34,35,36,38}

On October 30, 2026, HHS, the FDA’s parent department, published notice of a draft policy on six peptides, including semax and KPV. HHS says it does not intend to take enforcement action against state-licensed pharmacies, federal facilities or licensed physicians compounding them under section 503A, when all ten of its conditions are met. It covers only semax free base in the nose and KPV acetate on the skin or by mouth.^37,38

FDA staff reviewed KPV only as a skin cream or gel. For forms taken by mouth, HHS expects records showing people absorb enough of the drug; the FDA found no such study for KPV. Other conditions include a patient-specific prescription and one active ingredient per product, which leaves out blends such as semax mixed with selank.^2,38,1

The draft is not binding, is not an approval, adds nothing to the 503A bulks list and does not cover outsourcing facilities, compounders regulated under section 503B.^37,38

Rules in sport

Neither the World Anti-Doping Agency’s 2026 Prohibited List nor its 2027 list names any of the four. Both ban at all times substances no government health regulator has approved for human use, and the 2027 list names peptides as an example. Semax and selank, though, are registered as drugs in Russia.^39,40,1,7

What isn’t known

Questions to ask a clinician