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Compound Deep-Dive

Tier 2: Grey AreaA promising but niche neuroprotective agent best suited for those targeting age-related cognitive decline.

Cyclic Glycine-Proline

cGPCycloprolylglycineCyclo-Gly-ProCyclo(Gly-Pro)

Niche IGF-1 regulator for brain health.

Hype Risk

4/10

Noticeability

4/10

Evidence Tier

Emerging

Cost / Month

~$45

Niche Research

What it's actually good for

Focus

Mixed Evidence

Small trials show improved cognitive markers and memory retention in older adults with low IGF-1.

Recovery

Weak Evidence

Mechanistically linked to tissue repair via IGF-1, but direct human athletic recovery data is sparse.

Energy: neutralSleep: neutralMuscle: neutralLongevity: neutralMood: neutralImmunity: neutral

How it works

Cyclic Glycine-Proline (cGP) is an endogenous metabolite of IGF-1 that regulates its bioavailability by competing with binding proteins. Emerging human evidence suggests it may support cognitive function, microcirculation, and blood pressure regulation, particularly in aging populations.

cGP acts as a competitive inhibitor for IGF-binding protein-3 (IGFBP-3), preventing it from sequestering IGF-1 and thereby increasing the levels of free, active IGF-1 in circulation.

Safety

  • Generally well-tolerated as an endogenous molecule.
  • Long-term safety of high-dose synthetic supplementation is not yet established.
  • Consult a physician if you have conditions sensitive to IGF-1 levels.

The full StackRoast report adds

  • The exact dose, timing, and effective range to actually run it at
  • Where people go wrong with it — the dose-creep and timing traps
  • What Cyclic Glycine-Proline clashes with or duplicates in your stack
Roast My Stack →

Community Reality Check

Distilled from 65 threads
Confidence: medium

What users report

  • Mental clarity
  • Improved focus
  • Vascular health support

The catch

  • Expensive
  • Hard to source pure forms
  • Subtle effects

Side effects reported

  • None commonly reported
https://www.reddit.com/r/nootropicshttps://www.reddit.com/r/Biohackers

The Receipts

9 sources— studies, videos & links

Videos

The New Rules for Aging Better, Smarter, and Sharper

Smarter Not Harder Podcast

An in-depth interview with Dr. Amanda Wiggins on the science of cGP and neurovascular aging.

Tiny Titans of Life: Unravelling Nature's Small Wonders

ResearchPod

Explains the role of Dr. Jian Guan's research in identifying cGP as a master regulator of IGF-1.

Papers

Creators

Dr. Jian Guan

YouTube

The primary neuroscientist and researcher responsible for the majority of cGP clinical data.

Dr. Amanda Wiggins

YouTube

CEO of The cGP Lab and a frequent guest expert on longevity and neuroscience podcasts.

Clinical Sources

Taking Cyclic Glycine-Proline in a stack? Find out if the combination actually makes sense.

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