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PeptideAgent

Peptides for depression: what the evidence shows

By the PeptideAgent Editorial Team. Draft, pending editorial review.  Last verified

At a glance

No peptide has shown benefit for depression in a controlled human trial. Selank and semax are sometimes marketed for mood, but their human studies are in anxiety and stroke and their brain effects come from animal work. Antidepressants and psychotherapy are the evidence based treatments, with esketamine, ECT, or TMS for treatment resistant depression.

Evidence: Strongest: Animal-only evidence2 peptides gradedVerified: Verified Sep 22, 2026

Do peptides help with depression?

2 peptides are graded for depression on this page. The strongest grade is animal-only evidence, for selank and semax. Each one is weighed against the standard of care below, and the evidence table gives the grade and a note for every peptide.

What is the standard of care for depression?

Screen with a tool such as the PHQ-9 and assess suicide risk; psychotherapy (cognitive behavioral or interpersonal) and second generation antidepressants as first line; switch, combine, or augment when response is inadequate; esketamine, ECT, or TMS for treatment resistant depression.

Any peptide below should be judged against this baseline, not against doing nothing. Talk to a licensed provider before replacing or adding to an established treatment.

Which peptides have been studied for depression?

Ordered by strength of evidence for this use. Grades follow the methodology; each peptide page lists the individual studies.

Peptides studied for Depression with evidence grades
PeptideEvidence for this useNote
SelankEvidence: Animal-only evidenceMechanism work in rodents covers GABA, monoamine, and stress pathways; human studies are in anxiety, not depression. [2]
SemaxEvidence: Animal-only evidenceRaised BDNF in rat hippocampus after a single dose; no human depression study. [3]

Head-to-head comparisons

Cost and access

Price ranges, lawful channels, and insurance notes for peptides graded here. State rules are in the legal guides by state.

Frequently asked questions

Which peptide has the strongest evidence for depression?

Selank and semax have the strongest evidence among the peptides graded here, at animal only evidence. Selank: Mechanism work in rodents covers GABA, monoamine, and stress pathways; human studies are in anxiety, not depression. Semax: Raised BDNF in rat hippocampus after a single dose; no human depression study. No peptide graded for this use has a randomized human trial. [2] [3]

Is any peptide FDA approved for depression?

No. None of the peptides graded for depression is an FDA approved drug, so any use is outside an approved label and depends on the compounding and research status shown on each peptide page. [4]

Has any peptide been tested in a randomized trial for depression?

No. The best evidence for any peptide graded for depression is animal only evidence, so none has been shown to work in a randomized human trial for this use. [2] [3]

Sources

  1. [1]Comparative efficacy and acceptability of 21 antidepressant drugs for the acute treatment of adults with major depressive disorder: a systematic review and network meta-analysis. Lancet 2018PubMed 29477251, 2018
  2. [2]Peptide-based anxiolytics: the molecular aspects of heptapeptide selank biological activityPubMed 30255741, 2018
  3. [3]Semax, an analog of ACTH(4-10) with cognitive effects, regulates BDNF and trkB expression in the rat hippocampusPubMed 16996037, 2006
  4. [4]Drugs@FDA: FDA-approved drugs databaseFDA