I've spent 7 years testing peptides. I tested every one of them on myself first, then on the people (500+ clients) who trusted me enough to be next.
Most of what's written about peptides online is wrong in one of two ways.
- Either someone is selling you something and inflating what it does
- Someone is scared of it and is inflating what it might do to you
No one has actually provided a piece on what peptides are and which ones exist, how they work, or where to get them.
That's what this article is for.
What a peptide actually is
A peptide is a short chain of amino acids.
Insulin is a peptide, and it's the oldest one. Oxytocin is also a peptide. When you fall in love, peptides are involved. When you digest lunch, peptides are involved. Peptides are everything, and everything is peptides.
Put simply, a peptide is a message, and your body knows how to read that message. The ones people inject are just copies of those messages (synthetic ones) given back in larger doses.
How peptides are transforming the world
For most of history, if you wanted to lose weight, you had 3 options.
- Eat less
- Move more
- Or combine both
These work incredibly well, but it's not that simple. People have been losing the same twenty pounds and gaining them back for a 100 years, and they've been blaming themselves the whole time.
Peptides change this.
People on semaglutide just aren't hungry anymore. The voice in their head that used to scream about ice cream is now quiet because the signal that made them want it was suppressed via a peptide.
It took decades to find these molecules, but the principle is simple:
If hunger is a signal, you can change the signal.
The peptides people use to change that signal have shifted over the years. I'll walk through each one, starting with those built for fat loss.
The fat-burning group
These were the first peptides people reached for when they wanted to lose fat. Interestingly, some of them aren't technically peptides.
1) AOD-9604 is a fragment of growth hormone with just the fat-burning part kept in. Researchers in Australia in the 1990s thought: What if you could keep the piece that mobilizes fat and remove the pieces that mess with blood sugar and bone growth? AOD-9604 is what they came up with.
Over 900 people have tried it in trials. The results were solid, about 1.8 kg more weight lost than placebo over 12 weeks. It's also one of the safest peptides ever studied.
2) 5-Amino-1MQ is one of my favourites, although it isn't technically a peptide, but small molecule that blocks an enzyme called NNMT. In overweight people, NNMT goes into overdrive and burns through molecules your cells need to make energy. When you block it, your cells get their fuel back. They start burning fat instead of storing it.
What's interesting is that it doesn't touch appetite. Mice on it eat the same amount of food and lose weight anyway. The body just uses the food differently.
3) Tesofensine was developed for Parkinson's first, and it didn't work, but patients kept losing weight. Eventually someone ran the trials with that as the goal, and patients lost about 10% of their body weight. It works on the brain, not the gut, by suppressing cravings.
I use it to cycle-off GLP-1s. I actually just recently wrote more about it here.
4) Cagrilintide mimics amylin. This is a hormone your pancreas releases alongside insulin. Amylin tells your stomach to empty slowly and tells your brain that you're full. It's okay on its own. Combined with semaglutide (in a drug called CagriSema), it's approaching 16% weight loss.
I had a terrible experience with cagrilintide which I wrote about here.
5) Melanotan II was the original multi-pathway peptide. It does several things: tans your skin so you get that bronze tan, changes your appetite, affects your libido, etc. You don't want a drug to do several things at once because newer compounds split it apart.
6) LIPO-C isn't a peptide either, but a blend of vitamins your liver uses to process fat. You can think of it as changing oil before you upgrade the engine.
The GLP-1 group
GLP-1s started the peptide revolution.
For 60 years, weight loss drugs were either useless or dangerous (e.g. Ephedra was linked to heart attacks, strokes, seizures, etc.). Thanks to this, most got pulled from the market.
Then GLP-1 happened.
GLP-1 is a hormone your gut releases when you eat, and tells your stomach to empty slowly and your brain that you're done eating. But it only lasts for 2 minutes, so the trick was to make a synthetic version that lasts longer.
1) Semaglutide, better know under the brand Ozempic, lasts about a week per injection. People lose around 15% of their weight over a year. It's the most studied weight loss drug in history. It's FDA approved.
If GLP-1 fits your goal, this is the safest peptide to start.
2) Tirzepatide is semaglutide's stronger version because of the two receptors: GLP-1 plus GIP. These two together work better than alone. People lose about 22% of their weight, and about a third of patients lose 25% or more.
It's sold as Mounjaro or Zepbound. It's also FDA approved.
3) Retatrutide is definitely the hottest peptide in the world right now. It's the strongest one out of GLP-1 group, but it's not FDA approved. It hits three receptors: GLP-1, GIP, and glucagon. In late-stage trials, people lost almost 29% of their weight.
On top of this, it also clears fat out of the liver. Considering that fatty liver is one of the most common diseases in the world, retatrutide is positioned to be the best-selling drug ever.
4) And then we have Survodutide, Mazdutide, and Cotadutide. These are the variations of the same them, different combination of receptors, used on different populations.
- Survodutide is built for fatty liver
- Mazdutide came out of China for Asian patients who tend to develop metabolic disease at lower body weight than Westerners
- Cotadutide is daily injection instead of a weekly one
The growth hormone group
Growth hormone makes you lean. It tells your body to burn fat for fuel and your muscles to hold on to what they have. As you age, you make less of it. You get more fat, and less muscle. That's why people get softer in their 30s and 40s even though nothing else has changed.
You can inject growth hormone directly, but that has all sorts of consequences if not done right, so for the sake of brevity we'll keep that for another article.
The peptides in this group don't give you GH directly, but instead tell your body to make its own, in the right rhythm.
1) CJC-1295 (no DAC) is a peptide that tells your pituitary when to release a pulse of growth hormone.
2) Ipamorelin amplifies the pules. Older drugs in this category also raised cortisol and made you hungry, but ipamorelin doesn't.
CJC-1295 and Ipamorelin usually go together. The results aren't dramatic, but you get better sleep, faster recovery, and body composition improves slowly. It's a maintenance protocol.
3) Tesamorelin is more aggressive and more targeted. It's actually the only peptide the FDA has approved for fat loss in HIV-associated belly fat, but it works on visceral fat in general.
Visceral fat is the dangerous fat around your organs, and tesamorelin works well against it.
4) GHRP-2, GHRP-6, Hexarelin, and Sermorelin are older variations.
- GHRP-2 is stronger than Ipamorelin, but raises cortisol
- GHRP-6 makes you hungry, which is usefu if you want to gain muscle
- Hexarelin is the most powerful, also the one your body adjust to the fastest so you can't run it long.
- Sermorelin is the gentlest, and used to be FDA approved before the company stopped selling it for business reasons
The mitochondrial group
This is the part that fascinates me the most.
Inside every one of your cells, there are little factories called mitochondria. If they work well, you have energy and you're lean. If they don't work well, you don't work well either.
For a long time, nobody could do much about mitochondria, but that's changing with this group.
1) MOTS-c is a peptide discovered inside mitochondria DNA. We thought mitochondria DNA only coded for a few obvious things, but then somebody noticed that part of it was making this peptide that gets released into the bloodstream when you exercise.
MOTS-c acts on your body the way exercise does. It activates the same enzyme (AMPK) that gets activated when you run.
What this means is that you can get some of the metabolic benefits of exercise without exercising. I wrote more about it here.
2) SS-31 (Elamipretide) physically docks onto a specific spot on the inner mitochondrial membrane where energy gets made. When that spot misfires, electrons leak out and damage the cell, but SS-31 stabilizes it.
It's in late trials for heart failure.
3) Humanin is another peptide hidden inside mitochondrial DNA. It was first found because it protected brain cells from Alzheimer's damage, then researchers noticed the people with the highest levels of it also had the best metabolic health and lived the longest.
Levels drop with age, and whether you can put it back and reverse the drop is still an open question.
4) BPC-157 is the healing peptide. It comes from a fragment of a protein in stomach acid. This might sound funny, but no one fully understands what it does, but it speeds up healing of basically every kind of tissue.
I've heard hundreds of stories of people who suffered with chronic pain for years, but after taking BPC-157, the pain vanished.
5) Thymosin Alpha-1 (TA-1), ARA-290, and KPV are anti-inflammatory peptides. Obesity is partly an inflammation problem, and chronic inflammation is what blocks fat loss in a lot of people. These peptides lower that inflammation. TA-1 is approved for hepatitis in 35 countries, but not in the US.
6) SLU-PP-332 is the newest one, and it's actually not a peptide. It switches on the same genes endurance training would. I call it the "exercise pill." Mice on it ran 50% farther. It is still early, but if it works in humans, it's going to be a big deal. I wrote more about it here.
The brain group
Half of fat loss is happening in your body, and the other half is happening in your head. You can't just David Goggins your way through fat loss via willpower. It's finite.
What you can do is engineer your brain environment so the cravings quiet down.
1) Oxytocin is the cuddle hormone, but it's also a fullness signal, especially for emotional eating. People on intranasal oxytocin eat less (less fat), and the effect comes from feeling satisfied rather than from suppressed hunger.
2) PT-141 is a cleaner version of Melanotan (the peptide we mentioned in the beginning). It's FDA-approved for low libido, but it works on the same brain reward system that drives food cravings. Research on direct weight loss is still early.
3) Kisspeptin-10 sits at the link between reproductive hormones and metabolism. These two systems are tied together more tightly than people realize. If your hormones are off, your metabolism usually is too.
4) Setmelanotide is approved for rare genetic forms of obesity. It only works on people whose bodies have a specific broken signaling pathwaym, but in those people, it works dramatically, which proves that hitting the right brain receptor can produce massive weight loss.
The support group
These peptides don't burn fat, but they keep the rest of you running so you can do the things that do.
1) Semax is a Russian peptide that keeps your brain sharp during caloric restriction. When you're eating less, you usually think worse. Semax helps with that, but it also helps with focus. I use it daily, especially the intranasal spray. I wrote more about Semax here.
2) Selank is the other Russian one. It reduces anxiety without sedation of anti-anxiety drugs. Stress raises cortisol, cortisol stores belly fat, so keeping stress down matters more than people think. Low cortisol living is the way, and Selank makes it easier.
3) NAD+ is coenzyme your cells need to make energy, not a peptide. Levels drop as you age, so restoring it makes everything else work better.
4) GHK-Cu is a copper peptide that heals skin and hair. It also signals tissue repair throughout the body.
5) TB-500 is a healing peptide that works alongside BPC-157. Together they're the best recovery stack I've seen and tested.
How to actually use this
First, to clarify, you don't need 15 peptides as most people need two or three.
Second, ask yourself: What am I trying to accomplish by using peptides?
- If you have a lot of weight to lose, the obvious starting point (and the safest and most researched one) is a GLP-1 like semaglutide or tirzepatide. Add MOTS-c if you want to amplify the cellular side of things.
- If you're already lean and trying to optimize, CJC-1295 with Ipamorelin for the growth hormone side, and BPC-157 for recovery, will take you a looong way.
- If your specific problem is belly fat, there's Tesamorelin.
- If your problem is emotional eating, Oxytocin and Tesofensine address it directly.
- If you've beaten up your body, BPC-157 and TB-500 come first, before anything else.
You should never stack 5 peptides, and then wonder what each one is doing. Add one, watch what it does, then add the next.
What peptides won't do
Peptides are not magic. If you eat badly, sleep for for hours, and never move, there is no peptide that can save you.
But if you do the work and you want to accelerate it or you've reached the plateau and want to break through, then peptides are for you.
Where to get peptides
Peptides are research compounds. The good ones come from labs that test what they sell and ship with proof of what's in the vial. If the website doesn't tell you where their material was synthesized or if there is no legitimate COA, avoid.
Real Peptides is the one I personally use and trust. It's HPLC tested, mass spec verified, 99% purity standard.
It's been 7 years since I started, and I'm still learning. This field moves fast.
My advice to you is to start with one peptide, track everything, don't believe anyone (including me) without testing and seeing what it does for you first, and if it works build a protocol around it.
P.S.
Nothing in this article is medical advice. The peptides discussed are research compounds, sold for research use only and not intended for human consumption. Talk to your doctor before making decisions about your health.
