Peptides – although extremely noisy in the health, wellness and longevity arenas – seem to be a topic I’ve subconsciously filed under “not worth the bandwidth.”
But since my dear friend, Doris, asked, I thought I’d oblige.
An overview of the research has cleared up three things for me.
Firstly, I now know why I’d ghosted peptides. They’re popularly promoted as cure-alls in clickbait, and my brain has a fairly efficient spam filter for those. Although, given that there are a gazzilionty peptides, and therefore a gazzilionty potential extrapolated benefits, I can see the allure.
Secondly, peptides come with fancy acronyms and numbers, which, in my book, amounts to jargon. As a peptide layperson, if you’re going to bombard me with alphanumerical soup, I’ll think in another language.
Thirdly, and perhaps unsurprisingly, in the race to the spotlight, the marketing claims appear to be beating the evidence.
BOTTOM LINE
It turns out that peptides aren’t inherently new, always synthetic, anti-ageing or performance-enhancing. They are part of normal human physiology, and some have been used in medicine for donkey’s years.
Peptides, being mere molecules, aren’t themselves the problem; it’s just that not all peptides are equal. Some are established medicines with substantial human research behind them. Others are promising laboratory experiments that seem to have acquired a marketing department long before they’ve acquired convincing human evidence, which is all very exciting, until you realise that you might be the guinea pig.
But a lack of convincing human evidence doesn’t necessarily mean a peptide doesn’t work, or that it is unsafe. It means we don’t yet have enough reliable information to establish whether it works, for whom, at what dose, and with what risks.
It’s this tension that makes Doris’s initial question rather less straightforward than it first appears.
HOW TO
If Doris was contemplating “taking” a peptide, here’s what she might consider:
What exactly is she hoping to achieve?
Peptides have been suggested to:
- Enhance muscle recovery and growth
- Facilitate fat loss
- Improve skin health
- Help hair grow
- Help with metabolic regulation
- Etc, etc
Once Doris knows what she is after, she needs to find out which peptide is being promoted for that purpose.
For example, BPC-157 is commonly marketed for injury healing, improved muscle recovery and muscle growth.
GLP-1 agonists (commonly known as GLP-1s) are effective for weight loss, because they help with appetite regulation, satiety and reduce food intake.
Whilst collagen peptides are said to improve skin and joints.
Then Doris needs to somehow figure out if the peptide she is thinking of using has been shown to be safe for human use.
Some peptides have extensive human clinical research behind them (eg GLP-1s – have a look at my blog on those). Others require an inquiring eyebrow. BPC-157 has currently missed the “researched on humans” bar, with a systematic review actually concluding against its clinical use until properly regulated trials had been conducted.
But where would Doris find this information? I’d think her doctor or a trusted pharmacist. Or if she carries bags of salt over her shoulders as I do, she could do her own research on something like PubMed, searching the peptide’s name alongside human clinical trials and safety.
And if nobody can point her towards convincing human evidence, she might be looking at an interesting experiment rather than an established treatment.
THE SCIENCE
Having just referred to BPC-157, I am going to pick on it again, by way of illustration.
First off – for a synthetic peptide that’s already being sold in the wellness space, it still doesn’t have an approved brand name, so we’re stuck with the alphanumerical soup again! The GLP-1 agonist, semaglutide, is formulated into a synthetic peptide and marketed as either Ozempic or Wegovy.
If you want to take BPC-157, you have to ask for it by peptide. 😉
Sorry – I digressed…
BPC-157 is a synthetic peptide composed of 15 amino acids – the building blocks of a protein – linked together in a short chain.
Peptides are generally described as having fewer than 50 amino acids per chain, so compared to proteins, which are typically larger, more complex structures made from one or more amino acid chains, you could consider peptides amino acid challenged!
Given that peptides can contain up to approximately 50 amino acids, drawn from 20 different types, the possible combinations and arrangements of those amino acids mean that there are an astronomical number of different peptides, each potentially having different biological functions.
Our bodies naturally produce peptides; insulin is a great example of a peptide hormone. Defensins are also peptides, which protect us from invading microorganisms (aka little bugs). In fact, peptides are involved in many physiological processes: they can regulate body weight, mimic endorphins and are involved in reproduction, immunity and digestion.
But we can also manufacture peptides synthetically. BPC-157 is one such example and is promoted for tendon, ligament, muscle and joint recovery. It’s attracted attention because preclinical research, particularly in animals, has reported promising effects on tissue repair, inflammation and blood vessel formation.
But here’s the thing:
Just because something is biologically plausible, does not make it clinically so.
Just because a peptide influences a particular biological process in a laboratory, or improves healing in a rat, does not mean you will get the same result in a human.
Which is, in fact, the current status quo with BPC-157. A systematic review published in October 2026 identified only three eligible human studies involving 30 participants in total. Although some findings were encouraging, the studies were small, uncontrolled or otherwise methodologically weak. The reviewers found the evidence far too limited to draw reliable conclusions and recommended that BPC-157 remain in clinical trials rather than being used as an established treatment.
So, it’s not that I am actually picking on BPC-157 and claiming that it doesn’t work; it’s just that as yet, we do not have reliable human evidence that it works for the outcomes being marketed, or that it is safe.
How much evidence would then be enough?
Let’s look at semaglutide. Unlike BPC-157, semaglutide has undergone extensive human clinical testing. Large, controlled trials have demonstrated benefits for conditions, including type 2 diabetes and weight management. Researchers have also investigated appropriate doses, side effects, longer-term outcomes and the research is ongoing. And no, semaglutide is not risk-free; there is just a whole lot more evidence from which to make risk assessments.
I am not sure the same volume of information about BPC-157 is currently available to make informed risk assessments about its use. Certainly, the US FDA feels there is a lack of information regarding its safety in humans. The FDA is also concerned about possible immune reactions and impurities within compounded BPC-157 products.
Given the sheer number of peptides out there, it’s not just BPC-157 attracting scientific and commercial interest.
GHK is a peptide made up of just three amino acids that occurs naturally in the human body. When GHK binds to copper, it forms GHK-Cu, another naturally occurring compound. Both can also be manufactured.
Laboratory and animal studies suggest that both naturally occurring and synthetically manufactured GHK-Cu may influence fibroblast activity, stimulating the production and remodelling of collagen and elastin, which help maintain skin structure and elasticity. Research has also reported potential anti-inflammatory and antioxidant effects, as well as facilitate wound healing, tissue repair and the formation of new blood vessels.
These promising findings have helped fuel the marketing of GHK-Cu in topical skincare and hair-growth products.
Unfortunately, as far as skin health goes, there’s still not enough good-quality human research to confidently say how well it works. There has been some research into the effects of GHK-Cu on hair regeneration, including one promising study involving 18 people that reported improvements in eyebrow hair count and diameter. But these findings remain preliminary.
Peptides do work, but the devil is still hiding in the details.
And then I listened to a podcast in which an internationally recognised urologist, who has studied peptides for 12 years, expressed his frustration at the FDA’s 2023 restrictions on the compounding of 19 peptides.
Doris – this is more likely the reason why you are seeing so much about peptides on your feeds at the moment.
This doctor had been legally prescribing various peptides for his patients since 2014, and his patients did not report adverse side effects, but then suddenly he could no longer prescribe them. The FDA asserted that the lack of evidence for the safety of those compounded peptides was the reason for the ban. There are obviously other theories about what was really behind the imposed restrictions, but my takeaway from the podcast was empathy for this doctor. He seems to genuinely care for his patients and believes that certain peptides, prescribed for specific purposes, could help them. Yet regulations prevent him from offering treatments he considers appropriate.
And that needled me (pardon the pun!). Regulations are there to protect patients, but when they prevent a knowledgeable doctor from offering a treatment he/she believes could help, are those regulations truly protecting the patient or potentially denying them an opportunity?
I have experienced something similar as the patient, when the best treatment for me at the time was not officially allowed, because of bureaucracy and who stood to profit from it. I am happy to say that after a year of advocating for myself, I received the procedure I needed, and it was the best treatment I could have had at that time. It still benefits me 24 years later.
The circumstances were different, of course. But I know what it feels like when the person who understands your medical needs isn’t the person who ultimately gets to decide what treatment you can access. And when bureaucracy places limitations, some resourceful patients will find a way around – in the peptide sphere, that happens in the murky grey market.
I don’t believe there should be a free-for-all of self-prescribed peptide injections, but surely the goal would be to give suitably qualified medical practitioners, who understand the needs and idiosyncrasies of the individual sitting in front of them, the treatment options to make the best possible decisions together with their patient?
References with supported statements