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.

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.

Metabolic Nutrition Extrapolated

Does Short-Term Lysine Ingestion Raise 2-AAA, and What Does That Metabolite Signal Mean for Appetite and Glucose Control in 2026?

Yes — a 2026 isotope-tracer clinical study confirms that orally ingested lysine is catabolised to alpha-aminoadipic acid (2-AAA) within 30 minutes, peaking at roughly 2 hours post-ingestion. Lysine also stimulates a rise in unlabelled, endogenously produced 2-AAA — suggesting the amino acid load triggers a broader metabolic signal beyond simple catabolism, with documented links to beta-cell function and insulin sensitivity.

September 14, 2026 · 9 min read

Metabolic Performance Extrapolated

Does Resistance Training Combined With High Protein Intake Preserve Lean Mass During Rapid Fat Loss on Retatrutide in 2026?

No controlled trial has directly tested retatrutide combined with resistance training and high protein intake. Mechanistic evidence indicates that mechanical loading and leucine-triggered mTORC1 activation operate through pathways additive to retatrutide's triple-receptor pharmacology. The 2025 Coskun body-composition sub-study reported 35.4% of weight lost as lean tissue without exercise or protein controls.

September 11, 2026 · 9 min read

Metabolic Performance Extrapolated

Does GLP-1-Driven Gastric Emptying Delay Require a Structurally Different Protein Strategy During Resistance Training in 2026?

Yes — GLP-1-driven gastric emptying delay and appetite suppression create a protein delivery problem that a simple gram-per-kilogram target cannot solve. The roughly 36-minute solid-food emptying delay documented by Hiramoto et al. (2024) blunts postprandial aminoacidemia precisely when post-exercise mTORC1 sensitivity is highest, requiring faster-absorbing protein forms, pre-exercise loading, and deliberate leucine co-dosing.

September 10, 2026 · 9 min read

Metabolic Performance Extrapolated

Does Tesamorelin Reduce Visceral Fat Without Worsening Fasting Insulin or Training Recovery in Metabolically Active Adults in 2026?

Yes — with caveats. Across Phase III RCTs and a 2026 meta-analysis, tesamorelin reduced visceral adipose tissue by 15–20% over 26 weeks without significantly shifting mean fasting insulin, fasting glucose, or HbA1c. Training recovery data remain indirect: pulsatile GH and elevated IGF-1 support protein synthesis, but no controlled exercise-plus-tesamorelin RCT has reported post-exercise recovery endpoints in non-HIV metabolically active adults.

September 8, 2026 · 9 min read

Metabolic Performance Extrapolated

Does Adding Resistance Training to GLP-1 Treatment Improve Fat Mass and Insulin Sensitivity More Than GLP-1 Alone in 2026?

Yes — combining GLP-1 receptor agonist therapy with structured resistance training produces superior fat mass reduction and insulin sensitivity improvement versus GLP-1 monotherapy. A 2026 network meta-analysis across nine RCTs ranked the combination first on weight (SMD −1.04), fat mass, and HOMA-IR, with the exercise arm adding a statistically significant HOMA-IR benefit (SMD −0.28) that pharmacotherapy alone did not achieve.

September 4, 2026 · 9 min read

Metabolic Performance Extrapolated

What Protein Intake Actually Offsets Lean-Mass Loss During Semaglutide or Tirzepatide Cut Phases in 2026?

Current evidence sets the functional floor at 1·2 g per kilogram of total body weight per day during active GLP-1 cut phases. The 2025 AJCN joint advisory refines this to 1·5 g/kg of fat-free mass per day. Observed intake in GLP-1 users averages just 0·6 g/kg/day, directly explaining the 25–39% lean-mass fraction of total weight lost on semaglutide and tirzepatide.

September 3, 2026 · 9 min read

75%

mean increase in IGF-1 levels with CJC-1295 at 12 weeks

— Teichman et al., 2006, JCEM

All Articles Clinical Review Metabolic Metabolic Longevity Metabolic Nutrition Metabolic Oncology Metabolic Performance Metabolic Signalling Preclinical Regulatory

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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