"How are people actually buying peptides? If they aren't FDA approved, how is everyone getting them?"
I get this question every single day, so I'm going to answer it straight away instead of making you scroll to the bottom.
People are buying peptides through the "grey market". They're sold legally, but for a different purpose than the one written on the label.
How are people buying peptides YouTube video by Health Coach Kait
In this post I'll explain how that works, what peptides actually are (they're far less scary than most people think), how the three main GLP-1s compare, and what I learned first-hand from taking both retatrutide and tirzepatide. Some of it you won't find in the research.
How are people buying peptides without a prescription?
When you buy peptides like retatrutide or GHK-Cu online, the label will say "for research use only", and sometimes "not for human use". Both of these peptides are being studied, but neither is FDA approved for clinical use yet.
That label is the loophole. It's how people are getting GLP-1 drugs without a prescription. Anyone you see online using retatrutide, MOTS-c, GHK-Cu or BPC-157 has almost certainly bought it this way. The only exception is people taking part in the actual clinical trials.
You might also notice that people who talk about peptides online never link straight to a store. That's because, again, buying them this way is technically legal, but it's still a loophole. Take what you will from that.
What are peptides, really?
Peptides are not a scary new internet drug, and they are not steroids. Not even close.
"Peptides" is actually an extremely broad category. There are thousands of them. They're short chains of amino acids that act as signalling molecules in the body, telling a cell or a system to do something specific.
Some examples you already know:
Insulin is a peptide hormone. It signals your cells to take in glucose. It has been used for over 100 years and is life-saving for people with type 1 diabetes.
Some IVF hormones are peptides.
So not every peptide is a weight loss drug, and not every peptide is unregulated. If you want the full picture, I go deeper in what peptides are and why everyone is suddenly on them and the full list of FDA-approved peptides.
Not all peptides are for weight loss
Online, the word "peptides" is often used to mean weight loss drugs, specifically GLP-1s, which is confusing. Most peptides have nothing to do with weight loss:
GHK-Cu is being studied for hair and skin health.
BPC-157 is being studied for blood flow and injury repair.
Most people are mainly curious about the weight loss ones though, so that's what the rest of this post focuses on.
Semaglutide vs tirzepatide vs retatrutide: what's the difference?
The three main weight loss peptides are semaglutide, tirzepatide and retatrutide. The main difference between them is how many receptors they target.
Semaglutide (Ozempic, Wegovy): targets GLP-1. FDA approved.
Tirzepatide (Mounjaro, Zepbound): targets GLP-1 and GIP. FDA approved. Nicknamed "GLP-2".
Retatrutide: targets GLP-1, GIP and glucagon. Not approved yet, in phase 3 trials. Nicknamed "GLP-3".
Semaglutide (Ozempic) targets one receptor, GLP-1, which is the main one for appetite control. It slows digestion, keeps you fuller for longer and suppresses your appetite.
Tirzepatide (Zepbound) targets GLP-1 and GIP. GIP helps regulate how your body uses and stores energy, and it reduces some of the nausea that comes from targeting GLP-1 alone.
Retatrutide targets GLP-1, GIP and glucagon. Glucagon raises your metabolic rate, so you burn more energy and tap into fat stores more easily. The weight loss data on retatrutide is outperforming both semaglutide and tirzepatide, and people who have never been able to lose weight before are getting incredible results. It's also the one most people are buying from the grey market.
You'll see tirzepatide called "GLP-2" and retatrutide called "GLP-3". Technically there is no GLP-2 or GLP-3 receptor in this sense. They're just nicknames, and it's really not that serious.
The benefits of GLP-1s go beyond weight loss
This is the part that surprises people. GLP-1s also:
Reduce inflammation
Lower compulsive behaviour, and are being studied for addiction (alcohol and substances, but also gambling)
Appear to be protective for the brain
That's why a lot of people who are already metabolically healthy are choosing to microdose.
My experience on retatrutide vs tirzepatide
When I was taking a microdose of retatrutide, I got the benefits. My cravings and food noise dropped, inflammation went down and my discipline went up.
But the higher metabolic rate came with a cost. I felt wired, my sleep was a mess and I could feel my heart pounding. I was on the lowest dose and still tossing and turning all night. The poor sleep and the rise in my resting heart rate were ultimately why I switched to tirzepatide.
Is retatrutide the best GLP-1 for weight loss?
I know some people will disagree, but with the pros and cons weighed up, I think tirzepatide is the best option for most people. Here's why:
It's FDA approved and easy to access. If you're overweight or have high blood sugar, your doctor should be able to prescribe it, and there are online clinics too.
It causes less nausea than semaglutide. When GLP-1s first became popular, the common complaint was feeling too sick to eat, and that wasn't entirely wrong.
It doesn't wreck my sleep. Retatrutide works for a lot of people, but its effect on sleep and resting heart rate can't be ignored. On tirzepatide I feel calmer, my appetite is still under control, and I'm still getting the anti-inflammatory and longevity benefits.
No reconstituting. A prescription comes in a preloaded pen, ready to use.
If you asked me to pick one of the three, it would be tirzepatide. Hands down.
What does "reconstituting" peptides mean?
A GLP-1 prescribed by your doctor usually comes in a preloaded pen. Peptides bought online arrive as a freeze-dried powder, which is better for stability and shelf life. Reconstituting just means mixing that powder with a liquid so it can be used.
The supplies people use are bacteriostatic water, sterile 1 mL (100 unit) syringes and alcohol prep pads. Once reconstituted, peptides are stored in the fridge. I show the full process in the video above.
Before you start any peptide
Please research the peptide thoroughly first. Pep-Talk is a great resource. It covers the available evidence for each peptide, how strong that evidence is, the pros and cons and interactions with other medications.
And talk to your doctor, especially if you take other medications or have an existing health condition.
Tips to get the best results on a GLP-1
1. Supplement electrolytes from day one.
When you eat less, and especially less processed food, you take in fewer electrolytes, particularly sodium. Processed food is packed with them, so most people never think about it. Cut back and you need to get them from somewhere else, or you'll likely feel fatigue, light-headedness, headaches and muscle cramps. If that's happening to you on a GLP-1, it's very likely an electrolyte imbalance.
Choose an electrolyte with no added sugar and a decent amount of sodium. I use Sodii Everyday Hydration Salts every day.
2. Eat at least 30 g of protein at every meal.
This will make or break your results. If you don't hit it, you'll start losing muscle, your skin can sag and your face can start to look hollow. It's an easy fix.
3. If you can't eat enough, or you feel sick, your dose is too high.
Reduced food noise is a huge part of the benefit, but you still need to eat, and protein especially. If you're struggling to eat enough in a day or you feel nauseous, talk to your prescriber about lowering your dose.
Key takeaways
People buy unapproved peptides like retatrutide through the grey market, labelled "for research use only".
Peptides are a huge category of signalling molecules. Insulin is one. Most have nothing to do with weight loss.
Semaglutide targets GLP-1, tirzepatide targets GLP-1 and GIP, and retatrutide adds glucagon.
Retatrutide has the strongest weight loss data, but it raised my resting heart rate and ruined my sleep.
For most people, I think tirzepatide is the best balance of results, side effects and access.
Supplement electrolytes, eat 30 g of protein per meal, and lower your dose if you can't eat or feel sick.
FAQ
Are peptides legal to buy?
Many peptides sold online are labelled "for research use only" or "not for human use". Selling them for research is how they're legally available, but they aren't approved for human use, so you're relying on a loophole and on the seller's quality control.
What's the difference between semaglutide, tirzepatide and retatrutide?
The number of receptors they target. Semaglutide targets GLP-1, tirzepatide targets GLP-1 and GIP, and retatrutide targets GLP-1, GIP and glucagon.
Is retatrutide FDA approved?
Not yet. Retatrutide is in phase 3 clinical trials. Semaglutide and tirzepatide are FDA approved.
Which GLP-1 is best for weight loss?
Retatrutide has the most impressive weight loss data so far, but in my experience tirzepatide is the best all-round option because it's approved, easier to access, causes less nausea than semaglutide and doesn't affect my sleep.
Why do I feel tired or get headaches on a GLP-1?
Often it's an electrolyte imbalance, especially low sodium, because you're eating less. An electrolyte supplement without added sugar can help.
What does reconstituting a peptide mean?
Mixing freeze-dried peptide powder with bacteriostatic water so it can be used. Prescription GLP-1s come in preloaded pens, so they don't need it.
Conclusion
That was a lot, but I hope it clears up what peptides are, how people are getting them and whether one might be right for you. If you know someone who's curious about peptides, or who completely misunderstands them, send them this post.
Have a question you want me to answer next? Leave a comment on the video and I might cover it in a future one.
This post is for educational purposes only and is not medical advice. Always speak with your doctor before starting any medication or peptide.
