No human trialsNot FDA approved

N-Acetyl Semax Amidate side effects

Also known as: NA-Semax Amidate · NA-Semax-Amidate · NASA · N-Acetyl-Semax-Amidate Acetate · Ac-Met-Glu-His-Phe-Pro-Gly-Pro-NH2 · Ac-MEHFPGP-NH2

Updated Oct 24, 202642 sources

12 side effects reported for N-Acetyl Semax Amidate: 0 from studies and labels, 12 from users and guides. 10 come with the ways people manage them.

Cognitive

N-Acetyl Semax Amidate overview

Side effects users and guides report

What people post and what dosing guides list. These are reports, not measured rates.

From users and guides12

Community reports, competitor and vendor guides, media.

Worse sleep or insomnia
Reported by individual users; one guide lists sleep disruption when NA-Semax is taken later in the day
How people manage it
- Dose in the morning or early afternoon, as guides and users advise
Crash, headache and low mood as it wears off
One detailed r/Nootropics report; a guide lists tiredness as effects fade
How people manage it
- The user advises people in recovery from stimulant use to avoid it
Anxiety, overstimulation or irritability
Reported by some users; a guide lists overstimulation and irritability
How people manage it
- Lower the dose
- Pair with Selank or N-acetyl Selank amidate, as many users do
Headache
Occasional per guides, more often at higher doses; mentioned by users
How people manage it
- Lower the dose
Nasal or throat irritation, runny nose
Common and mild with sprays, per guides; extrapolated from Semax
How people manage it
- Alternate nostrils
- Switch to subcutaneous use
Brain fog
Reported by individual users
How people manage it
- Lower the dose or stop
Sleepiness at higher doses
One r/Peptides user
How people manage it
- Use a smaller dose
Lightheadedness
Some users at higher doses, per one guide
How people manage it
- Lower the dose
Awareness of heartbeat
One r/Nootropics user, on occasion
Fast tolerance
Repeated as hearsay by users
How people manage it
- Use it a few days a week instead of daily
- Cycle off
Stronger effect of cannabis and other drugs
One r/Nootropics user mid-cycle; a reply says Semax forms change tolerance to many drugs
No noticeable effect
Reported at 100 to 400 mcg over 3 days by one user
How people manage it
- Users suggest a higher dose or more time

Who should avoid it, and what not to combine

Stimulants and other CNS-active drugsSubstance
No interaction data exist for this variant. Guides advise against combining it with other nootropics or stimulants.
Pregnancy and breastfeedingCondition
No reproductive or developmental safety data for this variant.
Mania or bipolar-spectrum instabilityCondition
One guide urges caution because Semax-type peptides shift dopamine and may aggravate activation.
Anxiety disordersCondition
The Russian label for plain Semax lists anxiety disorders as a contraindication. No label exists for this variant, and some users report anxiety on it.

How much is known

No human trials

No human or animal study of this molecule exists. Two lab papers looked at acetyl-Semax: one found the acetyl cap changed copper binding and removed cell protection, and one measured resistance to breakdown (abstract not public). Every benefit quoted for it comes from Semax research. A chemical supplier and a drug company patent list it as a Semax derivative.