Semax Nasal Spray Dosing Guide — Calculator & Protocol

Semax helps your brain focus harder, learn faster, and handle stress without crashing. You can inject it subcutaneously like other peptides, but most people use it as a nasal spray. The nasal route gets it to your brain faster through direct nerve pathways, and you skip the needles entirely. This guide focuses on intranasal dosing since that's what the vast majority of people use.

What Is Semax?

Semax helps your brain focus harder, learn faster, and handle stress without crashing. You can inject it subcutaneously like other peptides, but most people use it as a nasal spray. The nasal route gets it to your brain faster through direct nerve pathways, and you skip the needles entirely.

How it works: Semax boosts BDNF, which is the main protein your brain uses to grow new connections and strengthen existing ones. More BDNF = better memory, faster learning, and more mental flexibility. It also supports dopamine and serotonin signaling (the same pathways responsible for motivation and mood) and protects neurons from oxidative stress. Think of it as giving your brain both the building materials and the protection plan at the same time.

The peptide itself is a synthetic fragment of ACTH, one of your body's own hormones. Researchers took the active piece of that hormone (the part that actually does useful things in your brain) and added a small molecular tail so it wouldn't break down before it could work. That tail is what makes the nasal spray format possible.

Semax was developed at the Institute of Molecular Genetics of the Russian Academy of Sciences and has been approved in Russia since 2011 for cognitive impairment, stroke recovery, peptic ulcers, and optic nerve atrophy. It's not FDA approved in the United States. In the US, it's only available as a research peptide or through compounding pharmacies.

There are three main variants, and they're not interchangeable:

• Semax (standard) is the base peptide described above. Most studied, mildest effects.
• NA-Semax (N-Acetyl Semax) has an acetyl group added for better stability and potentially stronger bioavailability.
• NA-Semax Amidate (N-Acetyl Semax Amidate) is the most modified version, with both acetylation and amidation. It's the strongest per-microgram and noticeably more stimulating. Some people describe it as "wired-in" focus.

Semax vs Selank: Quick Comparison

Semax and Selank get mentioned together constantly because they target opposite sides of the same coin: Semax is the gas pedal (focus, drive, motivation) and Selank is the stabilizer (calm, anti-anxiety, emotional balance). Both are nasal sprays. Different peptides, different mechanisms.

A lot of people stack them. Semax for the cognitive push, Selank to smooth out any overstimulation or edginess. The combo consistently gets described as clean focus without the jitters.

The most common stacking approach: Semax in the morning (for its activating effects during work) and Selank either alongside that morning dose or as an afternoon dose when stress ramps up. You can use both in the same session. Spray into alternate nostrils or go in sequence. Don't mix them in the same bottle.

How Intranasal Delivery Works

Semax goes up your nose instead of under your skin, and there's a good reason for that. The nasal lining has direct nerve pathways (olfactory and trigeminal) that act as a shortcut to the brain, bypassing the blood-brain barrier more effectively than a subcutaneous injection can for small peptides like this one.

The result: Semax reaches your central nervous system within minutes. You skip the GI tract and liver metabolism entirely. For a peptide where the brain is the target, intranasal delivery gives you faster onset (typically 5-15 minutes to noticeable effects) and higher brain bioavailability compared to injection.

The dosing math depends on two numbers:

• Concentration of the solution in your spray bottle (expressed as a percentage or mcg/mL)
• Volume per spray, the amount of liquid one pump delivers (typically 0.1mL for standard nasal spray bottles)

A standard nasal spray pump delivers roughly 0.1mL (100 microliters) per actuation. At a 0.1% concentration (1mg/mL, or 1,000mcg/mL), each spray delivers about 100mcg of Semax. At a 1% concentration (10mg/mL, or 10,000mcg/mL), each spray delivers about 1,000mcg (1mg) of Semax. Those two numbers (concentration and spray volume) are all you need. Our intranasal dose calculator handles the math automatically.

Nasal Spray vs Injection: Which Route Is Better?

This is one of the most common Semax questions, and the answer depends on what you're trying to get out of it. Most people use Semax as a nasal spray, and there's a good reason: all the Russian clinical trials used intranasal delivery. That's where the real human data lives. But you absolutely can inject Semax subcutaneously, and some people prefer it.

Here's what makes the nasal route unique: your nasal lining has direct nerve connections to the brain (the olfactory and trigeminal pathways). When you spray Semax in your nose, a portion of it travels directly into the central nervous system without having to cross the blood-brain barrier from the bloodstream. That nose-to-brain shortcut is why nasal Semax hits faster and may be more effective specifically for cognitive effects.

Injection gives you higher total systemic absorption (close to 100% vs 60-70% nasally), but systemic absorption isn't the same as brain delivery. For a peptide where the brain is the target, the nasal route's direct pathway matters more than raw bioavailability numbers suggest.

The practical breakdown:

Choose nasal spray if you want the most researched route, faster cognitive onset, no needles, and easy portability. This is the right choice for most people, especially if you're using Semax primarily for focus and mental performance.

Choose subcutaneous injection if you want once-daily dosing convenience, more consistent absorption (no variability from nasal congestion or technique), or you're already injecting other peptides and it's easier to add Semax to your protocol.

Pre-Made vs DIY Nasal Spray

You've got two options: buy a pre-made bottle that's ready to go, or reconstitute lyophilized powder into your own spray bottle. Most people buy pre-made. Some mix their own to save money or dial in a specific concentration.

If you're going the DIY route, you'll reconstitute the powder with bacteriostatic water (or preservative-free saline for nasal use), calculate your target concentration, and transfer the solution into a clean metered nasal spray bottle. Use our peptide reconstitution calculator to figure out how much solvent to add for your desired concentration.

Dose Calculation for Nasal Sprays

Intranasal dosing math is different from injectable peptide math. Instead of units on an insulin syringe, you're counting sprays.

Worked Example: 0.1% Semax Spray

• Concentration: 0.1% = 1mg/mL = 1,000mcg/mL
• Spray volume: 0.1mL per pump actuation (standard nasal spray bottle)
• Dose per spray: 1,000mcg/mL × 0.1mL = 100mcg per spray
• Target dose: 400mcg
• Sprays needed: 400mcg ÷ 100mcg = 4 sprays (2 per nostril)

Worked Example: 1% Semax Spray

• Concentration: 1% = 10mg/mL = 10,000mcg/mL
• Spray volume: 0.1mL per pump actuation
• Dose per spray: 10,000mcg/mL × 0.1mL = 1,000mcg (1mg) per spray
• Target dose: 600mcg
• Sprays needed: 600mcg ÷ 1,000mcg = 0.6 sprays. That's less than one full spray, which means the 1% concentration is too high for a 600mcg dose with this spray bottle.

This is exactly why concentration matters. A 0.1% spray gives 100mcg per actuation, easy to dose in 100mcg increments. A 1% spray gives 1,000mcg per actuation, only practical for doses of 1mg or higher. Or skip the math entirely. Use our Intranasal Dose Calculator to enter your spray bottle's concentration and volume. It tells you how many sprays equal your target dose.

Semax Dosing Protocols

Semax is measured in micrograms (mcg) per administration, taken intranasally 1-3 times per day. The half-life is short (roughly 30 minutes to a few hours for active metabolites), which is why multiple daily doses are the norm.

All doses refer to standard Semax. If you're using NA-Semax or NA-Semax Amidate, start at the lower end of these ranges. The modified variants are more potent per-microgram.

Dose in the morning and early afternoon. Avoid evening doses. The dopaminergic and stimulating effects can mess with sleep if you take it too late. Most people find that dosing after 3-4 PM makes it harder to fall asleep.

Using the Semax Intranasal Calculator

Our Intranasal Dose Calculator is built specifically for nasal peptides like Semax. No vial sizes, no insulin syringes. Just spray bottle concentrations and pump volumes, the variables that actually matter for intranasal dosing.

1. Open the Intranasal Dose Calculator.
2. Enter your spray bottle concentration. You can enter this as a percentage (0.1%, 1%) or as mcg/mL (1,000mcg/mL, 10,000mcg/mL). The calculator accepts both formats.
3. Enter your spray volume. Most standard nasal spray bottles deliver 0.1mL per pump. If your bottle specifies a different volume, enter that instead.
4. Enter your target dose in mcg (e.g., 200mcg, 400mcg, 600mcg).
5. Read your results. The calculator shows the exact number of sprays per dose, the dose per spray in mcg, and how to split sprays between nostrils for even delivery.

It also shows how many total doses your spray bottle contains based on its fill volume, so you can plan your supply. Track your Semax protocol alongside other nootropics in the Regimen app.

Track your Semax protocol, cognitive effects, and stacking schedule

• Smart reminders for each nasal spray dose
• Log cognitive effects and mood alongside dosing
• Track Semax + Selank stacking schedules together

Get Regimen Free

What to Expect: Timeline of Effects

Semax kicks in faster than most peptides, but the full range of benefits builds over weeks of consistent use.

Side Effects

Semax has one of the mildest side-effect profiles of any peptide in common use. Most people report zero sides at standard doses.

Semax doesn't cause the GI issues common with GLP-1 compounds or the injection-site reactions you get with subcutaneous peptides. The intranasal route is generally well tolerated. If nasal irritation becomes persistent, try reducing to once daily or switching to a spray bottle with a finer mist nozzle.

Storage

Pre-made Semax sprays from reputable sources are generally stable at room temperature after opening, but refrigeration is better for maximizing shelf life. DIY reconstituted solutions should always be refrigerated and used within 28 days. No exceptions on that one.

Keep spray bottles upright and away from direct sunlight and heat. Wipe the nozzle clean after each use to prevent bacterial contamination of the tip. For detailed peptide storage guidelines including travel considerations and temperature monitoring, see our Peptide Storage Guide.

Common Mistakes

Frequently Asked Questions