Peptides
Peptides for muscle growth, healing and fat loss, explained one compound at a time: what each one does, what has been tested in people, and what has not.
A few peptides are approved drugs with large trials. Many are sold on rat data alone. The guides below show which is which.
Start With Your Question
Most men open this page with one compound or one goal in mind. Pick the line that fits and go straight to the right guide from the peptides list.
Understand Peptides First
Categories, evidence and risk come before single compounds, above all for peptides for bodybuilding, where claims run ahead of trials. These six guides set up everything else on the peptides list.
What Are Peptides?
More than 80 peptide drugs are on the market and over 150 more are in human trials. What peptides are and how they signal.
Types of Peptides
Semaglutide cut weight 14.9% vs 2.4% on placebo in 1,961 adults; most research peptides have no such trial. The map of classes.
Growth Hormone Peptides
A year on an oral ghrelin mimetic added 1.1 kg of lean mass in people aged 60 to 81, with no change in strength.
Healing Peptides
BPC-157 has 30 patients in three uncontrolled studies; TB-500 has none. What the healing research really is.
Peptide Side Effects
Semaglutide bought online tested at 7.7 to 14.37% purity, and every sample held bacterial endotoxin. The real risks.
Peptide Research vs Human Use
Of 367 therapies tested in animals, only 5% went on to win approval for people. How to read peptide evidence.
Understand Categories Before Comparing Peptides
Peptides for bodybuilding should be learned in order: mechanisms, categories, evidence quality and risk. Single compound guides make more sense after that.
Start With Signaling
Peptides act through receptor signals, not the androgen receptor.
Separate the Groups
Healing, GH, metabolic and cosmetic peptides are not one class.
Check the Research Context
Rat data, human trials and user reports are read separately.
Protocols Need Context
Example structures explain discussion, not personal instructions.
Specific Peptides Explained
The peptides list, one compound at a time: mechanism, human data, side effects and how each differs from its category.
Working out units before you draw? The peptide calculator turns milligrams in the vial and millilitres of water into concentration and syringe units, live.
BPC-157 Explained
The whole human record is three small studies with 30 patients and no proper trial. Tendon, gut and rat data explained.
TB-500 Explained
No human has received the TB-500 fragment in a published study. Its one healing result is a 2026 rat Achilles study.
CJC-1295 Explained
One shot raised growth hormone 2 to 10 times for six days and IGF-1 1.5 to 3 times for 9 to 11 days in healthy adults.
Ipamorelin Explained
One dose gives a single growth hormone pulse that peaks at 40 minutes. Why it is called the clean GH secretagogue.
Rusfertide Explained
In polycythemia vera, 85% of patients were below 45% hematocrit by week 8. What it means, and does not, for TRT.
Glutathione Injections Explained
After an IV infusion, plasma glutathione had a half life of 14.1 minutes. What injections and pills can and cannot do.
Tesamorelin Explained
In the phase 3 trials behind its FDA label, visceral fat fell 15.2% while placebo added 5.0%. Trials, warnings and limits.
GHK-Cu Explained
In its one randomised wound trial, GHK-Cu gel closed diabetic foot ulcers by 98.5% vs 60.8%. What else is proven.
Coming Next
These guides, including several peptides for muscle growth, are being written. Each will join the peptides list above when published.
Peptides for Muscle Growth: What the Trials Show
GH peptides are sold for muscle. Here is what the human data shows at each step from hormone to muscle.
GH and IGF-1 go up
In healthy adults, one CJC-1295 shot raised growth hormone 2 to 10 times for six days and IGF-1 1.5 to 3 times for 9 to 11 days.
That part is well documented in phase 1 trials.
Lean mass moves a little
A year on an oral ghrelin mimetic added 1.1 kg of lean mass in people aged 60 to 81. Strength did not change.
Most injectable GH peptides have no body composition data at all.
Belly fat moves more
In the phase 3 trials behind its FDA label, tesamorelin cut visceral fat 15.2% while placebo added 5.0%.
That is a fat result in a specific patient group, not a muscle result.
Peptides for muscle growth raise hormones reliably but add little measurable muscle in the trials that exist. Treat big muscle claims with caution.
Two Kinds of Peptides
The peptides list mixes approved drugs with compounds that have never been tested in people. The difference is the evidence and the supply.
Approved
Semaglutide: 1,961 adults in one weight trial.
Tesamorelin, semaglutide, tirzepatide, bremelanotide.
Pharmacy, prescription, known dose and purity.
Measured and listed on the label.
Research
BPC-157: 30 people. TB-500: none.
BPC-157, TB-500, CJC-1295, GHK-Cu injections.
Online sellers; tested products often failed purity.
Mostly unknown in humans.
Only 5% of therapies tested in animals reached approval for people. Keep that in mind when you read about peptides for muscle growth.
6 Numbers From This Hub
These figures come up again and again across the peptides list. Each one is cited in the guide it comes from.
Peptide drugs on the market, with over 150 more in human trials.
People in every published human study of BPC-157 combined.
Humans given the TB-500 fragment in a published study.
Animal tested therapies that went on to win approval for people.
Lean mass added in a year by an oral GH secretagogue in older adults.
Visceral fat change on tesamorelin in its phase 3 trials.
Peptides for muscle growth are mostly a hormone story, not a muscle story. Check what was tested in people before anything else.
Peptides: Frequently Asked Questions
Short answers to the questions men ask most about peptides for muscle growth, healing and fat loss.
Do peptides help muscle growth?
Growth hormone peptides reliably raise GH and IGF-1, but muscle data is thin. A year on an oral GH secretagogue added 1.1 kg of lean mass in older adults with no change in strength. Most injectable GH peptides have no body composition trial.
What is on the peptides list on this site?
Core guides on what peptides are, their types, GH peptides, healing peptides, side effects and research quality, plus single compound guides on BPC-157, TB-500, CJC-1295, Ipamorelin, Rusfertide, Glutathione, Tesamorelin and GHK-Cu.
Has BPC-157 been tested in humans?
Barely. The whole human record is three small studies with 30 patients between them, none of them a proper controlled trial. Most of what is claimed comes from rat studies.
Which peptides are approved drugs?
Several are, including semaglutide and tirzepatide for weight, tesamorelin for visceral fat in a specific patient group, and bremelanotide for low desire in women. Many popular research peptides are not approved for human use.
Are research peptides safe to buy online?
Quality is a real problem. Semaglutide bought online without a prescription tested at 7.7 to 14.37% purity, and every sample contained bacterial endotoxin. TB-500 products did not consistently match their labels.
How do I work out syringe units for a peptide?
Use the peptide calculator on this site. Enter milligrams in the vial and millilitres of water added, and it shows concentration and units on a U-100 insulin syringe.
Explore Other Hubs
Every topic on Muscle Science has its own hub. Move to the next one from here.
Testosterone therapy, labs and side effects.
Hub →Bloodwork & HealthHow to read every marker on your report.
Hub →PED Side EffectsWhat each compound does to the body.
Hub →SteroidsCompounds explained one by one.
Hub →Cycle DesignHow cycles are structured and why.
Hub →PCTRecovery after a cycle.
Research peptides and what is known.
Evidence on popular supplements.
Hub →TrainingPrograms and lifting technique.
Hub →NutritionDiet, protein and calories for muscle.
