Peptide

From Retapedia, the free peptide encyclopedia
"Natty" redirects here. For the broader fitness term, see Natural bodybuilding.

A peptide is a short chain of between two and fifty amino acids linked by peptide bonds.[3] In contemporary sports and fitness culture, the term has acquired a secondary meaning as a shorthand for a class of synthetic and semi-synthetic compounds used to modulate growth, body composition, appetite, and tissue repair. The question of whether their use is compatible with natural bodybuilding — whether a peptide user is, in the vernacular, "natty" — is the subject of ongoing dispute among federations and athletes.[2]

This article catalogues 12 compounds frequently encountered in the peptide marketplace, the function each is researched for, and the verdict of the present rulebook.

Contents [hide]
  1. 1 Overview
  2. 2 List of peptides
  3. 3 Natty status
    1. 3.1 Criteria
    2. 3.2 Gray areas
  4. 4 Frequently asked questions
  5. 5 See also
  6. 6 References
  7. 7 External links

Overview

The compounds discussed below are diverse in mechanism. Some are growth hormone secretagogues; others are GLP-1 receptor agonists indicated for type-II diabetes and obesity; others still are short peptides studied in animal models for tissue repair. The catalogue does not endorse use; it summarises evidence and verdicts.

List of peptides

The following table lists each entry with its function and current classification under WADA and the federations consulted.

Current popularity⇵ Compound⇵ Function⇵ Verdict⇵
#1 NAD+ Boosts cellular energy production and DNA repair. Activates longevity enzymes. Improves metabolism and mitochondrial health. Cellular benefits proven, human longevity unproven. Natty
#2 Ozempic Reduces appetite and slows digestion for 15-21% weight loss. Improves blood sugar control. Lowers heart attack and stroke risk by 20%. Natty
#3 Tirzepatide Reduces appetite for 21% weight loss. Significantly improves blood sugar and diabetes. Reduces sleep apnea breathing disruptions by 50%. Natty
#4 Retatrutide Reduces appetite and boosts metabolism for 24% weight loss. Improves blood sugar, lowers cholesterol, normalizes liver fat in 90% of users. Natty
#5 BPC-157 Speeds healing of tendons, ligaments, muscles, and gut. Reduces inflammation and muscle soreness. Minimizes scar tissue formation. Natty
#6 Ipamorelin Stimulates growth hormone release without cortisol/prolactin effects. Improves sleep quality, recovery, and body composition. Minimal side effects. Natty
#7 TB-500 Speeds wound healing, muscle and tendon recovery. Reduces inflammation, improves joint mobility, minimizes scar tissue formation. Natty
#8 CJC-1295 Increases growth hormone and IGF-1 for 6+ days per injection. Improves body composition, muscle recovery, and fat metabolism. Weekly dosing. Natty
#9 MK-677 Increases lean muscle mass, bone density, and deep sleep quality. Enhances recovery and tissue healing. Risk of blood sugar issues. Natty
#10 IGF-1 LR3 Powerfully increases muscle growth, protein synthesis, and fat burning. Accelerates tissue repair and recovery. Risk of hypoglycemia. Natty
#11 CJC-1295/Ipamorelin Stack Boosts growth hormone 3-5x higher than individual peptides. Improves sleep quality, muscle mass, fat loss, and recovery. Minimal side effects. Natty
#12 RAD140 (Vosilasarm) Increases muscle and bone mass. Weight gain up to 10% in 28 days. Risk of liver damage and testosterone suppression. Not natty

Natty status

The classification "natty" or "not natty" is not a statement about legality, but about compatibility with the rules of natural sport federations and the spirit of the WADA Code.[1]

Criteria

An entry is marked "not natty" when any of the following is true:

  • The compound appears on the WADA prohibited list.[1]
  • A major natural bodybuilding federation explicitly bans the substance.[2]
  • The compound provides a performance advantage beyond what is achievable through diet, training, and recovery alone.

Gray areas

See also: Therapeutic use exemption

Therapeutic use of BPC-157 for tendon repair, or of semaglutide as a prescribed diabetes drug, occupies a contested middle ground. Practice varies by federation.[2]

Frequently asked questions

What does 'natty' mean?
Short for 'natural.' In fitness it refers to results achieved without anabolic steroids, growth hormone, or other prohibited performance-enhancing substances.
Are peptides considered natty?
Most performance-enhancing peptides are not. Therapeutic uses fall into a contested gray area.
How is a peptide's status determined?
By reference to WADA's prohibited list, natural bodybuilding federation rulebooks, and the intent of use.
What is the difference between natty and enhanced?
Natty denotes reliance on natural methods and legal staples; enhanced denotes anything reaching past the natural ceiling.
Can peptides be used medically and remain natty?
Therapeutic use for genuine injury is treated leniently by some federations and strictly by others.

See also

References

  1. a b c World Anti-Doping Agency. (2026). "Prohibited List 2026." Retrieved 12 May 2026.
  2. a b c Natural Bodybuilding Federation rulebook (2025 ed.). §4.2 Banned Substances.
  3. ^ Sikiric, P. et al. (2024). "Cytoprotection by BPC 157: a systematic review." PMC.
  4. Wilding, J. P. H. et al. (2021). "Once-weekly semaglutide in adults with overweight or obesity." NEJM, 384(11):989–1002.
  5. ^ U.S. Food and Drug Administration. "Compounded peptides advisory" (2025).

External links

Categories: Peptides | Performance-enhancing substances | Natural bodybuilding | Anti-doping | Bioactive molecules

This page was last edited on 12 May 2026, at 14:32 (UTC).

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