Semax – Dosage & Cognitive Effects


Here, I plan to compile useful information about a nootropic drug called “Semax”. I’ve first heard of Semax in the nootropics subreddit, testifying to its efficacy. Well, I’m going to dig deeper and do research on this particular drug. And if I get a chance to try it, share my experience too.

What is the Dosage for Semax?

semax bottle 1% solution
A bottle of Semax, 1% solution

So the normal range of dosage for Semax is around 300mcg to 600mcg; for new users they should always start at a extremely low dose and work their way up. The logic is that with any drug, you don’t want to overdose or have an adverse reaction. For overdosage, perhaps there could be an error in the way the pill was manufactured, or a mislabel, causing the amount of the active ingredient in the drug to be more or less than expected. For adverse reactions, taking a very small dose to test how your body reacts to the substance is a very smart precaution to take.

What are the Effects of Semax?

One property of semax is to drastically boost BDNF & NGF levels in certain parts of the brain. That translates to boosted neuroplasticity, and is possibly one reason why people have found semax to improve learning, memeory, and mood in the long term.

Let’s take a look at one study the National Institute of Health has published about Semax:

Semax is a synthetic peptide, which consists of the N-terminal adrenocorticotropic hormone fragment (4-7) (ACTH4-7) and C-terminal Pro-Gly-Pro peptide. Semax promotes neuron survival in hypoxia, increases selective attention and memory storage. It was shown that this synthetic peptide exerted a number of gene expressions, especially brain derived neurotrophic factor gene (Bdnf) and nerve growth factor gene (Ngf). Temporary dynamics of Bdnf and Ngf expression in rat hippocampus and frontal cortex under Semax action (50 mg/kg, single intranasal administration) was studied in this work. It was shown that the studied gene expression levels changed significantly both in the hippocampus and the frontal cortex tissues 20 minutes after the peptide preparation application. The expression levels decreased in the hippocampus and increased in the frontal cortex. Forty minutes after Semax administration both gene expression levels returned to the level typical of control tissues. After that they increased significantly by 90 minutes after experiment start. Bdnf and Ngf expression levels decreased up to the control levels by 8 hours after medicine applying maximum gene expression levels were attained. Thus, Semax administration results in rapid, long-term, and specific activation of Bdnf and Ngf expression changes in different rat brain departments.[1]

Implications for Semax helping Neurons survive in Low Oxygen Conditions

So there quite a bit of information that we can mine from this study. For starters, semax helps neurons in the brain survive in low oxygen conditions. So that means that if you were in a situation where there was low oxygen, you brain cells (neurons specifically) would last longer before dying of oxygen deprivation. So that sound useful if you were in a hypoxic extreme situations, like a forest fire or drowning. But what does this mean for regular users?

cat lying down squinting eyes in a daze about to go to sleepWell, our brain may actually experience hypoxia day to day, without us knowing it. For example, while we are sleeping some of us experience sleep apnea, which cuts of oxygen to the brain for short periods of time. A person with sleep apnea will notice that their quality of sleep is very low, and wakes up feeling fatigued and without feeling rested. That’s because the body & brain doesn’t get a chance to fall into a deep sleep while you are suffocating; the body has to repeatedly “wake” while you are unconscious so you don’t suffocate.

Another consequence of sleep apnea is that unfortunately some of your brain cells or neurons do die as a result of oxygen deprivation. And so with chronic sleep apnea you will end up significant brain damage in the long run. But semax could help counteract the loss of brain cells via sleep apnea, given that semax helps neurons survive in low oxygen conditions. Of course, if you know you have sleep apnea you should go to a doctor to have it treated.

Semax Improves Attention and Memory

study focus reading a book student vintage photoSemax also increases selective attention and memory storage. What does this exactly mean? Well the dictionary definition of selective attention is “the capacity for or process of reacting to certain stimuli selectively when several occur simultaneously.” In other words, selective attention is the ability to filter out many ongoing things while concentrating on a single one. This is is a useful skill to have, whether it be on the battlefield finding a target, or on the school grounds focusing on your studies. Your level of selective attention dictates how well you can block out distractions while you work; note that distractions can be treated in a few ways. One way is work in an low-stimuli environment that is free from distractions (ie. library). Another way is to improve your selective attention- and Semax seems to be able to do that.

And memory storage refers to how well or how much we can remember. So Semax improve how well we can remember & learn new things, according to the study. But how exactly?

Well further along in the text of the abstract, they mentioned that Semax affected the gene expression of BDNF (Brain Derived Neurotrophic Factor) and NGF (Nerve Growth Factor). Specifically, the BDNF and NGF levels in the brain’s hippocampus and frontal cortex significantly increased 90 minutes after Semax was administered to the rats. This increase lasted 8 hours after application, showing that “Semax administration results in rapid, long-term, and specific activation of BDNF and NGF expression changes in different rat brain departments”.

BDNF and NGF are both substances that are involved in the survival & growth of brain neurons; so improving BDNF and NGF also improves the function of the brain.

frontal lobe animation spinning skull anatomy brain
The frontal lobe is marked in red.

The brain’s frontal cortex is responsible for control over our motor function, problem solving, memory, language, judgement, impulse control, attention, and behavior. The frontal cortex is deeply involved with many cognitive tasks, and is aptly named the center of our executive function. We also need the frontal cortex for interpreting feedback from the environment. Given that the frontal lobe is so involved with different areas of our cognition, raising the function of the frontal lobe through the increase of BDNF and NGF levels also improves selective attention- as shown with Semax.

And an improvement in selective attention also means an improvement in memory; if your attention & focus to a particular subject is improved, then obviously you will be better able to remember it.

Finally, The hippocampus is the area of the brain responsible for the formation of new memories. This was determined when a famous patient called HM had a part of his hippocampus removed to prevent epilepsy. The consequence was that from that day onward, he was unable to form new memories. However, he still remembered his past.

So increasing BDNF and NGF levels in the hippocampus improves the function of the hippocampus, which is to learn new things to memory.

Related Links


  1. Effect of semax on the temporary dynamics of brain-derived neurotrophic factor and nerve growth factor gene expression in the rat hippocampus and frontal cortex [NIH]

What's Your Opinion?