What is Semax peptide?

Semax is a synthetic seven-amino-acid peptide derived from a fragment of adrenocorticotropic hormone (ACTH) and is commonly studied as an intranasal nootropic and neuroprotective peptide.

Semax is reported to nudge brain plasticity programs and stress-response biology, associated with increased BDNF and TrkB signaling.

Is Semax FDA-approved?

No, Semax is not an FDA-approved drug in the United States.

What is a typical Semax dosage in research planning?

Total daily intranasal amounts commonly fall around 0.6 to 1.5 mg per day, divided across two administrations.

Selank vs Semax — what is the difference?

Semax is associated with cognitive activation and neuroprotection, while Selank is associated with anxiolytic and stress-modulating effects.

Is Semax nasal spray legal in the UK?

Semax is not authorized as a medicine by the UK Medicines and Healthcare products Regulatory Agency.

Can Semax and Selank be used together?

Combining Semax and Selank is a research-community planning concept but is not clinically validated.

How fast does Semax work?

Intranasal Semax is described as fast-onset, with same-day effects on attention or task initiation reported.

Peptideintranasal

Semax

Semax is a synthetic heptapeptide analog of ACTH(4-10) studied in nootropic and neurotrophic research models.

Researched for

Neuroinflammation

Not yet audited

We have not published an audit on Semax. Everything below is reference material, not our own reading of the literature, treat it as a starting point for questions, not as a grade.

How it is thought to work

BDNF-related and neuro-signaling pathways.

Semax is a small synthetic peptide derived from a stress hormone (ACTH) that appears to boost brain plasticity signals (especially BDNF) and modulate neurotransmitter systems, with its strongest measurable effects seen when the brain is under stress, injury, or heavy cognitive load rather than at rest.

Reported side effects

The most commonly reported side effects are nasal discoloration (in about 10% of intranasal users), nasal irritation, anxiety or overstimulation (especially with stimulants or late-day use), sleep disruption, and elevated blood sugar in diabetics, though overall human safety data remain very limited.

Who should avoid it

People with diabetes, those who are pregnant or breastfeeding, individuals prone to anxiety, and anyone taking psychiatric or stimulant medications should avoid Semax outside of direct clinician supervision.

What sources report

Reference, not a recommendation

These are figures published elsewhere, reproduced with their source. Peppersite does not recommend an amount for Semax or for anything else, and nothing below has been checked against the study it came from.

Amount	Frequency	Route	Reported by
Standard: 0.6 to 1.5 mg/day · Low: sub-milligram per administration · High: up to ~1 mg/kg	Daily administration, often divided into morning and afternoon doses10-14 days for standard short course, 4-6 weeks for extended cognitive course · 4-6 weeks on, 2-4 weeks off	Intranasal solution, Subcutaneous injection	Peptide Dosing Protocols What it saysHide (secondary reference; provider confirmation required). Standard dosing for Semax is about 0.6 to 1.5 mg per day, typically split into two administrations.
300-600 mcg intranasally daily (or 1-3 drops/nostril of 0.1% solution)	once or twice daily10-14 day cycles · Repeat cycles per provider direction	intranasal	Commonly published practitioner dosing range - provider confirmation required.
200-600 mcg per dose (0.1% solution) for nootropic use; 3-6 mg per dose (1% solution) for stroke	2-3 times dailyRepeatable	intranasal	Peptide Protocol Wiki What it saysHide (secondary reference; provider confirmation required).
Referenced at 300-600 mcg (0.3-0.6 mg) daily in brain health protocols. Morning administration cited to carry cognitive benefit through the day. Rotation with other nootropic peptides between cycles referenced to maintain response.	Daily · Morning4 weeks on with rotation between cycles	nasal	Peptide Therapy Reference Text, internal KB v4 What it saysHide (Aug 2026), secondary reference; provider confirmation required.