Subject: Do Semax and Selank Need to Be Cycled?
From: Derek from Peptide Price <[email-masked]>
To: [email-masked]
Date: Thu, 19 Mar 2026 18:13:47 +0000
List-Id: <derekpruski.substack.com>

View this post on the web at https://derekpruski.substack.com/p/do-semax-and-selank-need-to-be-cycled

I get this question constantly, so let’s address it directly.
The short answer: it depends on the research protocol and administration frequency. Every research subject is going to respond a little differently. But here’s the framework that makes sense for most protocols.
What these compounds actually do
Semax and Selank are neuropeptides — they work on the brain’s neurotrophic and anxiety-regulating systems rather than hormonal pathways. Semax is primarily known for boosting BDNF (brain-derived neurotrophic factor), enhancing focus, cognition, and mental clarity in research subjects. Selank works on the GABAergic system and has anxiolytic effects — it reduces stress and anxiety markers in RS without sedation.
Neither works like a stimulant where you see an immediate on/off effect. The benefits build gradually and compound over time. That’s important context for understanding how to structure research protocols.
Why the effects build — and why that matters for cycling
With Semax, the building effect is tied to BDNF. Research — primarily from animal models and some small human trials — shows that BDNF elevation doesn’t just spike and drop. It develops over repeated administration and persists beyond the end of the protocol. BDNF promotes actual structural changes in the brain over time, which is why researchers often report that the cognitive effects feel more pronounced several weeks into a protocol than they did on day one.
Selank’s effects on the GABAergic and serotonin systems follow a similar pattern. Research suggests the anxiolytic effects tend to stabilize and strengthen over the course of a protocol rather than plateau or fade — though long-term human data here is still limited.
Because these effects accumulate, you’re not working with something that simply turns on and off. Neurological activity builds over time. And just like anything that builds, it’s smarter to let the RS return to baseline periodically rather than keeping things constantly elevated. Running a defined protocol with a deliberate break built in is the more thoughtful approach — and it gives you a cleaner read on how well the protocol is actually working.
The two approaches
Option 1 — Defined cycles with a break
Run a 4–8 week research protocol, then take 2–4 weeks off. This is the better approach for longer, higher-frequency protocols. Because of the BDNF-driven building effect, many researchers note that cognitive and mood benefits in RS persist well into the off period — the washout isn’t a cliff, it’s a gradual fade. You’re not losing everything the moment the protocol ends.
Option 2 — Intermittent use
Some researchers run Semax or Selank on an as-needed basis — a few days on, a few days off, or situationally around high-demand periods. At lower frequencies, the buildup effect is much less pronounced, and structured cycling becomes largely unnecessary. This is a perfectly valid research approach, especially when consistent daily effects aren’t the goal.
The bottom line
If you’re running a longer, consistent research protocol — build in 2–4 weeks off afterward. It allows the RS to return to baseline and gives the next protocol a clean starting point. If the protocol is intermittent by design, there’s a lot more flexibility.
Neither compound requires the rigid cycling structure you’d apply to something like a GHRH/GHRP stack. But keeping things constantly elevated without a break isn’t the right call either.
For research use only. Not for human consumption.

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