Dr. Pep

Peptides · ACTH(4-10) analogue (Met-Glu-His-Phe-Pro-Gly-Pro)

Semax: what the studies show

Every line below comes from a study, label or regulator record, checked by two models, with the source linked. Information, not medical advice. For adults 18+.

What it is

  • Semax is a synthetic seven-amino-acid peptide (Met-Glu-His-Phe-Pro-Gly-Pro) derived from a fragment of ACTH, but without hormone activity. It was developed in Russia, where FDA says it is a registered drug sold as 0.1% and 1% nasal drops.[1][2]
  • In the US it has no approval. FDA says semax injection and nasal products are marketed through wellness clinics and online sellers for anxiety, ADHD, stroke, memory and other uses.[1]

Bottom line

  • Human evidence for semax is mostly small, open or non-blinded studies from Russia, published in Russian-language journals, of nasal semax added to standard care in stroke, optic nerve disease and similar conditions. It has not been tested in modern, large, independent trials. No study tests the injected form that is sold in the US.[3][4][5][1]

What the human studies found

  • Acute stroke (1997, Russian journal): 30 patients given semax were compared with 80 controls on conventional therapy, with clinical scales and EEG. The authors reported faster recovery of motor and other deficits. Doses were 12 mg a day for moderate strokes and 18 mg for severe ones, for 5 or 10 days. The abstract does not describe blinding or randomisation, although this knowledge base labels it an RCT.[3]
  • Stroke rehabilitation (2018): 110 patients after ischaemic stroke, divided into early and late rehabilitation, with and without semax (6000 µg a day for 10 days, two courses 20 days apart). Semax was associated with higher plasma BDNF and better Barthel scores. It was not placebo-controlled, and the abstract does not say how people were assigned to semax.[5]
  • Optic nerve disease (2000): patients were split into three groups, with semax nasal drops, semax by endonasal electrophoresis, or control, all added to basic therapy. The authors reported better visual acuity, visual field and colour vision. Group sizes are not given in the abstract.[4]
  • Other reports include 187 patients with cerebrovascular insufficiency (2005, uncontrolled), 73 patients with brain injury after oxygen deprivation (1999), and glaucoma patients (2001). All are small, Russian-language, and have not been replicated outside the same networks.[6][7][8]
  • In healthy volunteers, an fMRI study of 24 people found intranasal 1% semax (14 people) was associated with a larger default-mode-network subcomponent than placebo (10 people) 5 and 20 minutes after dosing. This is a brain-imaging measure, not a clinical benefit.[9]
  • Motor neuron disease (2007): a 27-patient open-label trial in sequential groups gave 12 mg a day intranasally in two 10-day courses. It was open label and non-randomised. The authors reported that semax did not change the course of muscle denervation or clinical scores, though it improved a quality-of-life score linked to emotional state.[10]

Known risks and side effects

  • FDA found no pharmacokinetic studies in humans by any route and no safety data for subcutaneous semax. The only route in the literature was intranasal, and most papers did not discuss safety.[1]
  • FDA raised a bleeding concern from one report that semax has antithrombotic properties, and an abuse-potential concern from the rat dopamine data. It also flagged immune-reaction risk from injected peptides.[1]
  • In patients with brain injury after oxygen deprivation, EEG showed episodes of paroxysmal activity after semax injection in some cases, and the authors advised EEG monitoring at the first injection.[7]

Legal status

  • As of 2026-10-09 semax is not approved in the US. FDA's category 2 page lists semax (heptapeptide) among nominated-but-withdrawn substances, citing immunogenicity risk and limited safety information.[11]
  • FDA's briefing document for the July 23-24, 2026 advisory committee evaluated semax for cerebral ischaemia, migraine and trigeminal neuralgia and proposed not adding it to the 503A bulks list. It said only two references were available, with too little detail, and that they showed a lack of effectiveness.[1]
  • ABC News reportedly said the committee narrowly voted to recommend adding semax and five other peptides to the 503A list, against FDA staff advice. This is a secondary report. FDA had not posted the outcome as of 2026-10-09. The vote is advisory and non-binding.[12]

Sources

  1. [1] July 23-24, 2026, Meeting of the Pharmacy Compounding Advisory Committee – FDA Briefing Document for Semax-Related Bulk Drug Substances (Semax (free base) and Semax acetate)
  2. [2] Semax, an analogue of adrenocorticotropin (4-10), is a potential agent for the treatment of attention-deficit hyperactivity disorder and Rett syndrome.
  3. [3] [Effectiveness of semax in acute period of hemispheric ischemic stroke (a clinical and electrophysiological study)].
  4. [4] [Evaluation of therapeutic effect of new Russian drug semax in optic nerve disease].
  5. [5] [The efficacy of semax in the tretament of patients at different stages of ischemic stroke].
  6. [6] [Semax in prevention of disease progress and development of exacerbations in patients with cerebrovascular insufficiency].
  7. [7] [Use of semax at a follow-up of patients with posthypoxic encephalopathy].
  8. [8] [Semax in the treatment of glaucomatous optic neuropathy in patients with normalized ophthalmic tone].
  9. [9] Effects of Semax on the Default Mode Network of the Brain.
  10. [10] [The study of chronic partial denervation and quality of life in patients with motor neuron disease treated with semax].
  11. [11] FDA: Certain bulk drug substances for use in compounding that may present significant safety risks (503A/503B category 2)
  12. [12] ABC News: FDA advisers narrowly vote to add 6 peptides to drug compounding list (2026-07-24)