Peptide science at the intersection of diet, metabolism, and performance.

Peptidegenics

An independent reference on how peptides interact with diet, metabolism, body composition, and training. No supplements sold. No affiliates. No agenda.

Browse by Metabolic Context

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Caloric Deficit & Fat Loss

How peptides affect fat oxidation, muscle retention, and metabolic rate during energy restriction.
Anabolic Environment & Muscle

Growth hormone axis peptides, mTOR, protein synthesis, and what training stimulus has to do with it.
Fasting & Metabolic Switching

Peptide interactions with fasting windows, ketosis, autophagy, and insulin signalling.
Performance & Recovery Nutrition

Pre- and post-training peptide timing, recovery nutrition context, and substrate utilisation.

Latest Articles

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Preclinical Extrapolated

What Does the 2026 Evidence Actually Quantify for BPC-157, TB-500, and GHK-Cu in Trained Adults — and Where Does the Chain Break?

For all three compounds, the evidence chain breaks at the species boundary. A 2026 UCLA scoping review of 565 studies across six unapproved peptides found that BPC-157, TB-500, and GHK-Cu have no completed human RCTs measuring body composition or athletic recovery as primary endpoints. Preclinical mechanisms are quantified; human performance outcomes are not.

October 1, 2026 · 9 min read
Preclinical Extrapolated

How Does the 2026 Demirtaş Critical Review Grade the Preclinical Evidence for BPC-157 in Rodent Ischemia–Reperfusion Injury — and What Should Performance Practitioners Actually Conclude?

The 2026 Demirtaş critical review in International Journal of Molecular Sciences (IJMS 27(18):8344) appraises the preclinical IRI evidence for BPC-157 as mechanistically coherent but structurally limited: consistent rodent results across oxidative stress, endothelial, and apoptotic endpoints, yet concentrated in a single research group, delivered exclusively via parenteral routes, and without a validated pharmacokinetic bridge to human performance contexts.

September 30, 2026 · 10 min read
Metabolic Performance Extrapolated

Does MK-677 Meaningfully Increase Lean Mass Without Worsening Cardiometabolic Risk in People Trying to Improve Body Composition in 2026?

MK-677 (ibutamoren) produces a statistically significant but modest lean-mass gain of approximately 1.6 kg above placebo over 12 months in the only controlled human trial. It simultaneously raises fasting glucose, reduces insulin sensitivity, and generated a congestive heart failure signal that terminated a separate elderly-population trial. The lean-mass benefit is real but narrow, and the cardiometabolic cost is not negligible.

September 29, 2026 · 9 min read
Metabolic Performance Extrapolated

Does Retatrutide's Glucagon Receptor Component Amplify or Attenuate Lean-Mass Loss During Resistance Training in 2026?

Retatrutide's glucagon receptor (GCGR) component creates a dual-edged lean-mass signal: it drives hepatic amino acid catabolism via urea-cycle upregulation — a direct lean-mass liability — while simultaneously increasing energy expenditure through fat oxidation, reducing substrate pressure on muscle protein. Resistance training resolves this tension by redirecting circulating amino acids toward myofibrillar synthesis rather than hepatic gluconeogenesis.

September 25, 2026 · 9 min read
Metabolic Performance Extrapolated

Do CJC-1295, Ipamorelin, and MK-677 Actually Improve Lean Mass or Visceral Fat in Athletes, or Is the 2026 Evidence Still Mostly Animal Data?

Mostly animal data, with one narrow human exception. A 2026 UCLA Health review of 565 studies across six unapproved peptides concluded that human evidence is sparse and marketing claims substantially outpace the clinical record. MK-677 has the strongest human dataset, but its one meaningful RCT enrolled elderly adults rather than athletes, and total fat mass rose alongside lean-mass gains.

September 24, 2026 · 9 min read
Clinical Review Extrapolated

What Does the 2026 Systems Medicine Multi-Omics Data on Semaglutide Reveal About Cross-Tissue Substrate Flux and Diet Timing?

The 2026 systems medicine review of semaglutide (Tandfonline, Expert Review of Clinical Pharmacology) integrates proteomic and metabolomic datasets with major RCT outcomes to show that semaglutide reconfigures substrate flux across liver, skeletal muscle, and adipose tissue simultaneously. These molecular shifts begin 4 to 8 weeks before measurable weight loss, creating a distinct periodization window for diet and training intervention.

September 24, 2026 · 10 min read
75%
mean increase in IGF-1 levels with CJC-1295 at 12 weeks
— Teichman et al., 2006, JCEM

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Peptidegenics covers the intersection of peptide biochemistry, nutrition science, and metabolic physiology. Every article is grounded in published research. Nothing is sold here.

The Metabolic Applicability Rating on each article answers the question the performance-focused reader actually asks: does this evidence apply to how I actually eat and train, or is this a lab finding I cannot act on?

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