Semax: Nootropic Benefits, Dosage, & Side Effects

A comprehensive review of Semax, covering its nootropic benefits, dosage, and side effects.

In this Semax review, we’ll take an in-depth look at this popular nootropic. We’ll also go over how Semax works in the brain, provide information about the benefits, side effects, and where you can buy it online.

Semax has gained popularity recently as a nootropic, making its way into the mainstream thanks to its purported neuroprotective and neurorestorative properties.

It is mostly used in Russia and Ukraine, although it hasn’t been evaluated, approved for use, or marketed in most other countries.

Semax has become popular due to its efficacy in treating many conditions such as stroke, transient ischemic attack, memory and cognitive disorders, peptic ulcers, optic nerve disease, and boosting the immune system.

Let’s take a look at what Science says about Semax and how it can impact your brain health.

Semax in Summary

Semax is a peptide that has shown promise as a cognitive enhancer and neuroprotectant. It is commonly used in Russia as a treatment for stroke and other brain injuries and has shown some efficacy in clinical trials. Semax is also being studied as a possible treatment for Alzheimer’s disease, ADHD, and depression.

The main benefit of Semax appears to be its ability to improve cognitive function, although it also has neuroprotective properties. It is unclear how Semax works in the brain, but it may work by increasing levels of BDNF and NGF.


  • Helps reduce the breakdown of enkephalins (neurotransmitters that play a role in pain relief)
  • Shown to improve cognitive function in studies
  • May help protect the brain from damage caused by stroke or other injuries


  • Limited human research
  • Difficult to find outside of Russia

What Is Semax?

N-acetyl Semax, or Semax, has recently gained traction due to its nootropic activity. It is a synthetic heptapeptide developed by Russian researchers and derived from the fragment of adrenocorticotropic hormone (ACTH) – ACTH (4-10).

The development of Semax, a synthetic peptide drug, uses only 4 of the 39 amino acids found in the ACTH peptide.

Semax can be called MEHFPGP in a single-letter form containing seven amino acids with the Met-Glu-His-Phe-Pro-Gly-Pro composition. It was first developed in the 1980s and has been used extensively in Russia as a treatment for various brain conditions.(1)

In addition to its nootropic effects, Semax has also been shown to have anti-inflammatory, antioxidant, regenerative, vasodilatory, and neuroprotective properties. Due to Semax’s poor oral bioavailability, the optimal administration method is through a nasal spray or subcutaneous injection.

How Does Semax Work In The Brain?

In animal studies, Semax has been shown to work in the brain by rapidly elevating the levels and expression of brain-derived neurotrophic factor (BDNF) and its signaling receptor TrkB in the hippocampus.(2)

Specifically, it has been found that Semax increases both BDNF mRNA and protein concentrations in this area, as well as inducing an increase of TrkB expression in the dentate gyrus.

Semax causes the increase of dopamine and serotoninergic systems of the brain to encourage activity-dependent AMPA trafficking, which means the circuits in heavy use get cognitive priority.

Intranasal NGFBDNF memory

Here we can see the changes in the all-important levels of neurotrophins, BDNF, and NGF.

The Semax dosage was the equivalent of 515 mcg for a 65 kg human. As you can see, there is a huge spike in NGF in the retina at three hours and small increases in the hippocampus and frontal cortex.

Semax is well known to rapidly induce BDNF, which could explain why the first time point starts at almost double the control levels.

It’s important to know that human handling is a rich experience for animals like rats and can increase neurotrophin levels just in itself.

NGF placebo control

1, brainstem; 2, cerebellum; 3, frontal cortex; 4, hippocampus; 5, retina

This graph compares the expression of NGF between rats that have been intranasally administered Semax compared to those administered water. This conflicts with other studies showing a spike in NGF levels in the brain’s frontal cortex and low retina levels.

BDNF placebo control

1, brainstem; 2, cerebellum; 3, frontal cortex; 4, hippocampus; 5, retina

This graph compares BDNF expression between intranasally water-given rats and intranasally given Semax rats.

The drop in prefrontal trophic levels could be because the placebo rats were continuously scared of being picked up by a huge hand and shoved a syringe into a very personal area, which can induce neurotrophins themselves.

Also, low prefrontal BDNF levels seem advantageous for certain ages and tasks.

Hippocampal BDNF is useful in improving a varied collection of cognitive domains.


Meta-analysis of the data recorded in the brain of young volunteers has shown that effective cognitive training increases activation of the medial prefrontal cortex, the region located in the DMN frontal subcomponent.

The main function of the medial cortex, closely connected to the limbic system and reticular formation, consists in the “regulation of brain states, modification of cortical tone, cravings, and affective life.”

effects on serotonin

Semax alone (0.15 and 0.6 mg/kg, i.p.) failed to alter these tissue and extracellular (dopamine) concentrations (data are not shown).

Dopamine is not increased from Semax alone. Serotonin, however, does face a significant rise from the drug’s actions.

More serotonin can explain the behavioral improvements people report of a more stress-resistant mood and higher energy levels, making it effective for conditions like chronic fatigue. The arrow signifies the point of administration.

Importantly, the larger Semax dose witnessed a lower increase in serotonin turnover.

800% BDNF increase

This is why people claim that Semax can induce 800% of the amount of BDNF.

In reality, these neurons came from a postnatal period that is too drastically different from a grown adult brain. Neurons are reactive to neurotrophins and ligands in general.

Also, this is not the amount of protein. This amount of mRNA needs to be proven highly related in glial primary cultures during postnatal days 1 to 2 to be taken as accurately representing the amount of protein made.

Additionally, Semax activates both serotonergic and dopaminergic brain systems, leading to an increase in both serotonin and dopamine concentrations.

These effects on neurotransmitters are thought to be responsible for producing antidepressant-like and anti-anxiety effects after taking Semax, along with its ability to reduce behaviors associated with chronic stress.

Although its mechanism of action is not clear from the scientific evidence, Semax is hypothesized to work in the brain by acting on specific receptors, such as the melanocortin (MC) receptors.(3)

Studies have indicated that Semax can competitively antagonize the action of the full agonist α-melanocyte-stimulating hormone (α-MSH) at MC4 and MC5 receptors, suggesting that it may act as a partial agonist or antagonist of these receptors.(4)

What Is Semax Used For?

Semax is most commonly used as a nootropic supplement to promote memory, focus, and cognitive function. In addition to improving brain health and functioning, Semax has also been shown to be effective at treating various mood disorders, including depression and anxiety.

A clinical trial involving healthy volunteers conducted in 2018 revealed that Semax could boost the fMRI default mode network activity compared to its placebo counterpart.(5)

A 1996 study uncovered that when people ingested 250-1000 micrograms per kilogram of Semax during their 8-hour workday, they experienced increased attention span and short-term memory. Astonishingly, the effects were more prominent after the shift concluded where exhaustion and fatigue were inevitable.(6)

The study revealed that the treatment group’s memory recall was significantly better than the control group, with a 71% correct response rate compared to just 41%, following one day of being administered Semax.

A separate study of 110 stroke patients revealed that those treated with Semax experienced a spike in BDNF levels, which is correlated with accelerated rehabilitation.(7)

What Are The Benefits Of Semax For Cognition?

Semax has been shown to offer various cognitive benefits, such as:

  • Enhanced cognition
  • Improved focus and concentration
  • Increased memory capacity and recall
  • Improved problem-solving abilities

Semax is also known for its anti-anxiety effects, helping to reduce stress levels, improve mood stability and reduce insomnia. Its capacity for boosting BDNF benefits both neurogenesis and neuroplasticity, offering protection against cognitive decline over time.

Where To Buy Semax Online?

It can be difficult to find high-quality Semax online, as there has been a huge increase in the number of online retailers selling counterfeit nootropic supplements.

To ensure you are purchasing high-quality Semax that is both safe and potent, it is best to purchase directly from a reputable manufacturer or authorized reseller.

We highly recommend, which is an American vendor. They provide all different Semax nasal spras with varying prices.

They offer fast 2-5 days US delivery and ship worldwide to over 50 countries.

What Do People Say About Semax On Reddit?

Let’s take a look at some of the comments and experiences people have shared about Semax on Reddit:

According to jdee:

“I have used this for a few months now and I really like it. It is more expensive than other cognitive enhancers at the 1% concentration, but it has been well worth the money. It has helped me to be more productive while running my own business, and it also helps me to stay on top of my daily tasks.”

According to Crunkle:

“Semax is definitely top tier nootropic. The only downside I’ve found to it is the high cost, but it works so well that I can’t complain.”

And finally, according to molarsmall:

“I don’t know if this stuff is any different than other cognitive enhancers, but it has helped me more than anything else I’ve tried. I use the 1% concentration, and a single dose helps me to be focused, productive, and efficient for hours. I’ve also noticed an improvement in my ADHD symptoms, which is a huge bonus.”

How Do You Take Semax For Cognitive Enhancement?

Semax should be administered as 2 drops into each nostril 1-2 times per day for between 3 and 14 days to improve cognitive functioning. A single bottle of this powerful nootropic contains 60 individual 50 mcg doses, meaning it can last anywhere from 3 to 10 days, depending on how frequently it is used.

If you’re brand new to Semax, we recommend starting with 1 dose per day for the first few days before gradually increasing the dosage to 2 doses per day. Semax is most effective when cycled on and off, with at least 4 weeks in between cycles.

Semax is best taken on an empty stomach in the morning, as it can interfere with sleep and cause insomnia if taken too late in the day and cause GI upset in some individuals.

Always consult with a qualified healthcare professional before starting any new supplement regimen, especially if you have pre-existing health conditions or are currently taking any medications. Do your research and always speak with a medical professional before changing your current routine.

A single drop of this powerful formula contains either 50 mcg (at 0.1%) or 500 mcg (at 1%), making it great for customized dosing according to individual needs.

Administering Semax precisely is paramount; just 2 to 3 drops should be pipetted into each nasal passage. If additional doses are required, give them at 10–15 minutes intervals for maximum effectivity.

For most individuals, one dose will consist of 200-2000 mcg (dependent on body weight), while an entire treatment cycle suggests taking 800-8000mcg based upon 3–30 mcg/kg for 7–70 kg, respectively. Prolonged symptoms may require repeating the course if necessary.

After suffering a traumatic brain injury, patients are often given three doses of 1,400 to 3,500 mcg – that’s 40-50 mcg per kilogram – over the course of five days. This treatment is sometimes stretched out as far as 2 weeks for maximum effectiveness.

To boost mental energy and avoid fatigue, 2-3 drops through each nasal passage 3 times during the morning for 3–5 days is the typical starting dosage prescription. The optimal daily amount of intake is between 400–900 mcg/day.

Conditions affecting the optic nerve, a daily dose of 600-900 mcg is administered in 2 or 3 drops into each nostril twice or thrice a day for over 10 days.

Pediatricians prescribe a daily dose of 200-400mcg for children ages 7 and up with mild cognitive impairments, administered as 2 drops into their nasal passages twice daily. With consistent use over 30 days, this treatment can help improve mental functioning, cognitive processes, and motor skills.

Please note that these dosage recommendations are provided only for guidance – the optimal dosage of Semax will vary from person to person, depending on age, weight, and medical conditions.

What Are The Side Effects Of Semax?

According to our research, Semax is very well-tolerated by most users, with few reported side effects. However, some users experience a slight burning sensation in the nasal passages or mild mucus membrane irritation after administration.

Other possible side effects of Semax include:

  • Headaches
  • Nausea
  • Vomiting
  • Drowsiness

It’s worth noting that most of the reported side effects are mild and transient. If you’re brand new to Semax, we don’t recommend stacking it with other nootropics or supplements, as this can increase the risk of adverse side effects .

What Nootropics Are Similar To Semax?

Nootropics that are similar to Semax include: Noopept, Selank, and Piracetam.

  • Noopept is a cognitive-enhancing supplement purported to work by increasing acetylcholine signaling and expression of BDNF/NGF in preclinical studies. It protects from glutamate toxicity while enhancing inhibitory neurotransmission within the brain.
  • Selank, like Semax, acts as a Melanocortin Stimulating Hormone-like Peptide (MSH) in the brain, leading to diverse benefits associated with cognitive performance and health. Also, it is frequently suggested for its anxiolytic effects, immune support, gastric protection abilities – and notably useful during opioid or alcohol addiction withdrawal periods.
  • Piracetam profoundly impacts the vascular system and enables better microcirculatory flow. It was the first cognitive enhancer that didn’t cause sedation or heightened stimulation levels, making it popular with many users.

All three of the above nootropics improve brain function by modulating various neurotransmitters, such as glutamate and acetylcholine while supporting healthy neurotransmitter levels. Semax and Noopept are specifically potent in BDNF, while Selank is well-known for its anxiolytic effects.

Piracetam is the only nootropic on the list that is well-studied, making it a common go-to for newcomers to the world of nootropics. In addition, there are limited data on the long-term efficacy and safety of Semax and Selank.

What Brain Supplements Can Semax Be Stacked With?

Semax can be stacked with other nootropics to improve cognitive performance and overall well-being further. For example, it can enhance the beneficial effects of Noopept when taken together due to their similar mechanisms of action.

Other potential Semax stacks include:

  • Semax + Piracetam
  • Semax + Aniracetam
  • Semax + Alpha-GPC

Alpha-GPC is a cholinergic compound that can boost acetylcholine levels in the brain, while Aniracetam, like Piracetam, is a popular racetam and “mood-booster.” These two nootropics are designed to support a healthy mood and improve memory, learning ability, and focus.

We recommend starting with a simple foundation stack if you’re brand new to the jungle of nootropic supplements. This includes nootropic blends like NooCube. NooCube contains 13 science-backed ingredients that work synergistically to stimulate the mental function and assist in cognitive ability.

Although NooCube doesn’t contain any of the racetams used in the above stacks, it does contain Alpha-GPC and L-Theanine, which can produce similar benefits when taken together. It’s also an all-natural nootropic supplement and free of common side effects, making it a great alternative to Semax if you’re new to nootropics.

If you’re interested in learning more about NooCube, you can check it out right here.

Frequently Asked Questions (FAQ)

Let’s take a closer look at some of the most common questions people have about Semax.

How Long Does It Take For Semax To Work?

Semax lasts between 2 to 10 hours, depending on your dosage and tolerance level. You may start to notice the effects within 30 minutes, although many users report that it takes anywhere from 2 to 3 hours to see the full benefits.

How Does Semax Make You Feel?

Semax makes you feel clear-headed and energized, giving you the mental stamina needed to focus on difficult tasks for long periods. It also helps reduce feelings of anxiety or stress, so it can be a good choice if you have an upcoming exam or presentation at work. Some people experience euphoria or a ‘high’ feeling, although this may vary from person to person.

Does Semax Show Up On A Drug Test?

No, Semax does not show up on drug tests. This is because the compound is not currently included in the World Anti-Doping Agency’s list of prohibited substances, which many sports organizations and companies use to test for drug use.

What’s The Half-Life Of Semax?

The half-life of Semax is between 2 and 10 hours. This means that it takes up to 10 hours for the body to reduce the concentration of Semax in the bloodstream by half.

Is It Safe To Use Semax?

Semax is considered generally safe and well-tolerated by most users. However, it may be best to consult your doctor before using Semax or other nootropic supplements. This is especially important if you are pregnant or breastfeeding, have a health condition like hypertension or diabetes, or are taking prescription medications that interact with nootropics.

Is Semax Legal?

In the United States, Semax is an unscheduled drug and not currently approved by the FDA for medical use. However, it is legal to buy and use Semax as a research chemical or supplement under the Dietary Supplement Health and Education Act of 1994 (DSHEA).


So what do we know about Semax?

Semax is a peptide that has shown promise as a cognitive enhancer and neuroprotectant. It is commonly used in Russia as a treatment for stroke and other brain injuries and has shown some efficacy in clinical trials. Semax is also being studied as a possible treatment for Alzheimer’s disease, ADHD, and depression.

The main benefit of Semax appears to be its ability to improve cognitive function, although it also has neuroprotective properties. It is unclear how Semax works in the brain, but it may work by increasing levels of BDNF and NGF.

Biohackers use Semax to boost focus, improve mental clarity, and treat disorders like ADHD. Semax is considered safe and well-tolerated, although it may produce side effects in some people.

Semax: Nootropic Benefits, Dosage, & Side Effects
Semax: Nootropic Benefits, Dosage, & Side Effects 2

What is Semax and which is the best version of it? In this Semax review we discuss all of its variants, benefits, dosage, side effects, and where to buy it.

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Sources, Studies, and Scientific Research
  1. Eremin, Kirill O et al. “Semax, an ACTH(4-10) analogue with nootropic properties, activates dopaminergic and serotoninergic brain systems in rodents.” Neurochemical research vol. 30,12 (2005): 1493-500. doi:10.1007/s11064-005-8826-8
  2. Effect of Semax on Tyrosine Phosphorylation of Trkb Receptors in the …
  3. Filippenkov, Ivan B et al. “Antistress Action of Melanocortin Derivatives Associated with Correction of Gene Expression Patterns in the Hippocampus of Male Rats Following Acute Stress.” International journal of molecular sciences vol. 22,18 10054. 17 Sep. 2021, doi:10.3390/ijms221810054
  4. panelAlfioBertoliniPersonEnvelope, Author links open overlay, et al. “Drug-Induced Activation of the Nervous Control of Inflammation: A Novel Possibility for the Treatment of Hypoxic Damage.” European Journal of Pharmacology, Elsevier, 24 Jan. 2012,
  5. Lebedeva, I S et al. “Effects of Semax on the Default Mode Network of the Brain.” Bulletin of experimental biology and medicine vol. 165,5 (2018): 653-656. doi:10.1007/s10517-018-4234-3
  6. Kaplan, A., et al. “[PDF] Synthetic ACTH Analogue Semax Displays Nootropic-like Activity in Humans: Semantic Scholar.” Neuroscience Research Communications, 1 Jan. 1996,
  7. “The Efficacy of Semax in the Tretament of Patients at Different Stages of Ischemic Stroke.” Просмотр Статьи,

Jacob Kovacs is a cognitive neuroscientist and author at WholisticResearch, specializing in nootropics and neuroactive peptides. His expertise in neuroscience and psychopharmacology bridges cognitive science with drug development. Kovacs’ work focuses on enhancing cognitive functions and brain health through innovative, efficient neuroactive compounds that overcome traditional pharmacokinetic challenges. His contributions are pivotal in advancing the understanding and treatment of neurological diseases.