What Peptides Actually Are
August 2026 · 7 min read
Before anything else: I'm a paid affiliate for Feel Peptides. If you buy through my link or my code, I earn a commission. I have not used their products. I'm not a doctor or a nurse, and nothing here is medical advice. Now you know all of that up front, and you can read the rest with it in mind.
Peptides come up in my DMs constantly. Every time I go looking for a straight answer, I get one of two things. Hyped posts promising stuff nobody can promise, or research papers I need a dictionary for. There isn't much in between. So here is my try at the in between.
What a peptide is
A peptide is a short chain of amino acids. Amino acids are what your body uses to build protein. String a few together and you have a peptide. That's really the whole definition.
What makes them interesting is their job. Peptides are signals. They're one of the ways your cells talk to each other, carrying instructions from one part of your body to another. That's basic biology, and it's true whether or not any particular peptide product does anything useful for a person.
Your body already makes hundreds of them. Insulin is a peptide. So is oxytocin, the one people call the love hormone. None of this is new or strange.
The idea behind taking them, and why I hold it loosely
Here's the pitch you'll hear. Your body makes fewer of these signals as you age, so if you top them back up, things work better again.
The first half is partly true. Some of these signals do get quieter with age. Growth hormone is the one people bring up most. But not all of them drop. Some actually go up. So "your peptides decline as you get older" is a simpler story than the real one.
The second half is where I'd slow down. Turning a quiet signal back up is a hypothesis. It isn't a finding. I have not seen good human studies showing that works for the peptides sold online. Anyone who tells you it's settled is ahead of the science.
Collagen peptides are a different animal
If you've bought collagen peptides at Target, you might be confused about how that relates to the vials people talk about online. Fair question.
Collagen peptides are sold as food. You drink them. Digestion breaks most of them into amino acids and small pieces, and your body uses those wherever it needs them. The risk is about like a protein powder. Low for most people, but not zero. The FDA doesn't check supplements before they go on sale, so third party testing still matters.
They're the same class of molecule as the injectable kind. What's different is the size, the route into your body, and how they're regulated. When people online say "peptides," they almost always mean the second kind.
How they're taken
Most of them show up as a freeze dried powder. It looks like nothing at all, just a little dust in the bottom of a bottle. It has to be mixed with liquid before use. The word for that is reconstitution.
I'm not going to walk you through that part. Which liquid, how much, how it's stored, how the bottle gets handled. Those are sterile technique questions, and getting them wrong can give you an infection. That's a conversation for a licensed provider, not a blog post. Same goes for dosing.
From there it's either a small injection or a nasal spray, depending on the product.
Why not a pill? Peptides are fragile and hard to absorb. Your gut enzymes break most of them apart. The ones that survive are too big to pass through your gut wall easily. That's why shots and sprays exist. It isn't a hard rule though. A few peptide medicines have been built into pills, and oral semaglutide is the best known one.
What we know and what we don't
This is the part most posts skip, so I want to be careful here.
Peptides as a whole are well understood. The science is real. Several peptide medicines went through full testing and are prescription drugs today.
But the specific ones sold in the wellness world are all over the map. Some have years of research behind them. Others mostly have lab studies and animal studies, with very little in actual people. A lot of what gets shared online started as a promising idea in a petri dish. Then it got repeated until it sounded proven.
Here's the big one. Most peptides sold for wellness are not FDA approved for what people are buying them for. Many are labeled for lab research only. That is not a small detail. It means nobody has checked them for safety or results the way an approved medicine gets checked. It also means the product was not made or tested for going into a person at all.
The risks I want you to have in front of you
I'm going to give you a buying checklist in a second, so it's only fair I give you this first.
- Infection. Injecting anything carries a risk, and it goes up when you're doing it yourself.
- You don't know how clean it is. Anything labeled research only was not made to go into a person, so nobody checked.
- Dosing without a provider means dosing without a safety net.
- Nobody has studied how these mix with your medications. Or what they do over years.
None of that means never. It means this is a decision to make with someone who knows your history, your meds and your bloodwork. Not off a blog post, including mine.
What I'd ask before trying any of it
- Who made it, and can they prove what's in it? Ask for a third party Certificate of Analysis for that exact batch. Check that the testing lab is a real accredited one. A COA tells you what's in one sample and how pure it is. It does not mean the product is safe.
- What does the research say about this one? Not peptides in general. The specific one you're looking at.
- Is it approved? And if it isn't, do I understand what that means?
- Have I talked to someone who knows my history? Someone who knows your meds and your labs.
- Do I have bloodwork from before? Without a starting point you have no way to know what changed.
- Am I doing the free stuff first? Sleep, protein, walking, lifting. Nothing in a bottle beats those, including anything I would ever link to. I'm an affiliate for a peptide company and I still think that's true.
The brand I partnered with
I recently became a paid affiliate for Feel Peptides. Let me be straight about what that means and what it doesn't.
I have not used their products. The peptides I've tried came from somewhere else, and my NAD+ was given to me at a clinic, not something I mixed at home. So I have no results to report and I'm not going to invent any. When I've used their stuff long enough to say something honest, I'll write that post.
Here's what I actually looked at. They publish third party Certificates of Analysis, and they say their products are made in a US facility that's registered with the FDA and follows cGMP practices.
Those words get thrown around a lot, so let me slow down. Being registered with the FDA just means a company put itself on a list. That's it. It is not an approval. It is not an endorsement. The FDA has even warned companies for using it that way. The FDA also does not hand out cGMP certificates. And like I said above, a Certificate of Analysis tests one sample. It does not mean safe.
So that paperwork is better than nothing. It is not the same as approved. You deserve both halves of that, not just the flattering one.
I get commissions for purchases made through links in this post. My code Janet10 gets you 10% off your first order. They also have a subscription that keeps the discount going. If you do that, read the billing terms first and check how you cancel. A subscription also means you're signing up to keep using something that isn't FDA approved. That's worth a real think.
Have a look at Feel Peptides →
Paid link. These products are not FDA approved. This is not medical advice. Please talk to your own doctor before starting anything new.
Frequently asked questions
What is a peptide, in one sentence?
A short chain of amino acids that works as a signal in your body, carrying instructions between cells. Your body already makes hundreds of them.
Are collagen peptides the same thing?
They're the same class of molecule, but sold and used completely differently. Collagen peptides are food that you drink and digest. The ones people talk about in wellness are mixed with liquid and injected or sprayed.
Are peptides FDA approved?
Some peptide medicines are approved prescription drugs. Most of the ones sold for wellness are not approved for what people buy them for, and many are labeled for lab research only, meaning they weren't made or tested for human use.
Why are they injected instead of swallowed?
Digestive enzymes break most peptides apart, and the survivors have trouble crossing the gut wall because of their size. A few have been engineered into pills, but most haven't.
Do I need bloodwork first?
Nobody can stop you from skipping it, but I'd want baseline labs, and any provider worth seeing will want them too. Without a starting point you have no way to know what changed. Which numbers make sense is a question for them, not me.
Are you a medical professional?
No. I'm a creator sharing what I've learned and what I've tried. Nothing here is medical advice. Always talk to a real provider before making health decisions.
Janet Von Schmeling
Orlando mom of two and the creator behind Planet Janet TV. I have no medical or scientific training. I share the real tips, trips, and wellness finds I actually use. Come say hi on Instagram.
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Read it next →Sources: general reading on peptide biochemistry, plus FDA guidance on establishment registration and unapproved drugs. I've deliberately not linked clinical trial literature for specific peptides, because pointing you at a trial for a specific condition would amount to making a medical claim I'm not qualified to make. This is education, not medical advice.