If it seems like everyone is suddenly talking about peptides, you’re not imagining it.
Peptides are showing up everywhere—from weight-loss medicine and metabolic health to conversations about recovery, skin rejuvenation, healthy aging, immune function, sexual health, and body composition.
And increasingly, patients are coming into my office saying:
“I saw this peptide online. What do you think?”
Or even:
“I already bought it. Can you tell me how to use it?”
That is exactly why I think we need to talk about peptides.
I am not interested in pretending that patients aren’t hearing about these products or purchasing them online. I would much rather help you understand what a peptide actually is, what the research does and does not show, what is FDA-approved, what is still experimental, and where the risks are.
First: What Is a Peptide?
Peptides are short chains of amino acids, the same building blocks that make up proteins.
Your body naturally produces thousands of peptides that function as signaling molecules. They can influence hormones, metabolism, immune activity, tissue repair, digestion, neurological signaling and many other biological processes.
This isn’t alternative medicine. Peptide-based drugs are already an established part of conventional medicine, and numerous peptide therapeutics have received FDA approval for specific indications.
The controversy comes from putting very different compounds under the single umbrella of “peptide therapy.”
Some peptides are FDA-approved medications supported by large clinical trials.
Others have promising early human research.
Some have primarily laboratory or animal data.
And others are being aggressively promoted online despite having remarkably little human safety information.
Those are not the same thing.
The Peptides You’re Probably Hearing About
1. GLP-1 and Related Metabolic Peptides
Semaglutide and tirzepatide have completely changed the conversation around obesity and metabolic medicine.
Tirzepatide, for example, targets both GIP and GLP-1 receptors and is FDA-approved for chronic weight management under the brand name Zepbound.
These medications can influence appetite, satiety, glucose regulation and body weight.
They are powerful medications—not cosmetic shortcuts—and appropriate patient selection, nutrition, muscle preservation, medication review and clinical monitoring still matter.
And now there is another name you’re likely to start hearing much more often.
2. Retatrutide: The New “Triple Agonist”
Retatrutide (LY3437943) is one of the most talked-about investigational metabolic drugs.
Unlike semaglutide, which primarily targets the GLP-1 receptor, or tirzepatide, which targets GLP-1 and GIP receptors, retatrutide activates three receptors:
GLP-1 + GIP + glucagon.
That is why you may hear it described as a triple-receptor agonist or “triple G” medication.
The excitement is understandable.
In a randomized Phase 2 clinical trial published in The New England Journal of Medicine, retatrutide produced substantial, dose-dependent weight reduction over 48 weeks in adults with obesity.
But here’s the part social media often leaves out:
Retatrutide is still an investigational drug.
As of August 2026, Phase 3 studies are continuing, including trials evaluating retatrutide against tirzepatide and studies examining different dose-escalation schedules.
It is not currently FDA-approved.
More importantly, FDA specifically states that retatrutide is not a component of an FDA-approved drug and cannot be used in compounding under federal law.
Yet patients can find products labeled “retatrutide” being sold through websites and social-media channels.
FDA has already issued warning letters regarding companies marketing purported retatrutide products as unapproved drugs.
That creates an enormous distinction between:
receiving an investigational medication in a regulated clinical trial
and
buying a vial online that says “retatrutide.”
Those are absolutely not equivalent.
If you see retatrutide offered online today, please understand what you’re looking at before putting it into your body.
3. GHK-Cu: The Copper Peptide
Another peptide gaining tremendous attention is GHK-Cu, or glycyl-L-histidyl-L-lysine copper.
This one is particularly interesting because GHK is a naturally occurring human peptide that binds copper.
Research has explored its potential role in:
- extracellular-matrix remodeling
- collagen-related activity
- skin repair
- wound healing
- tissue regeneration
- inflammation
- antioxidant activity
The biological mechanisms are intriguing, and laboratory and preclinical literature provides a legitimate scientific basis for continued research.
Female patient practicing self-care: Signature No Tox Botox Facial Rejuvenation
GHK-Cu is probably best known today in skin-care and regenerative-aesthetic applications.
Researchers are continuing to study it. A registered 2026 clinical trial, for example, is evaluating topical GHK-Cu gel for acute skin-wound healing.
However, we need to make another important distinction:
Topical GHK-Cu and injectable GHK-Cu are not the same conversation.
FDA has specifically identified injectable GHK-Cu as potentially presenting safety concerns related to immunogenicity, aggregation and peptide-related impurities, and notes that human safety data for injectable use are limited.
For non-injectable GHK-Cu, the regulatory situation is different. In May 2026, FDA placed non-injectable GHK-Cu back into Category 1 of bulk substances under evaluation for potential use in 503A pharmacy compounding; that does not mean GHK-Cu itself has become an FDA-approved drug.
This is precisely why I don’t like the phrase:
“Peptides are safe.”
Which peptide?
At what dose?
Through what route?
Manufactured by whom?
For what medical indication?
And supported by what level of evidence?
Those questions matter.
4. BPC-157
BPC-157 has become almost legendary in sports, recovery and biohacking circles.
You will hear claims involving tendon repair, gastrointestinal healing, musculoskeletal injury and recovery.
The problem is that enthusiasm has moved much faster than clinical research.
FDA reports that there is limited safety information for proposed human routes of administration and identifies concerns including immunogenicity and peptide-related impurities.
That doesn’t mean researchers should stop investigating BPC-157.
It means we should stop speaking about an experimental compound as though its safety and effectiveness have already been established.
5. CJC-1295 and Ipamorelin
These peptides are often marketed together in “anti-aging,” body-composition and recovery programs because of their interaction with the growth-hormone axis.
Again, the biology is interesting.
But the marketing is often much more confident than the clinical evidence warrants.
FDA reports limited clinical data for CJC-1295 and has identified serious adverse events associated with it, including increased heart rate and systemic vasodilatory reactions. FDA has also raised safety and immunogenicity concerns regarding compounded ipamorelin.
That’s information a patient deserves to hear before somebody sells them a vial.
6. Thymosin Alpha-1 and TB-500
These are also increasingly discussed in longevity, immune and regenerative-medicine communities.
Thymosin alpha-1 has been investigated for its immunomodulatory effects.
TB-500, commonly described as a thymosin-beta-4 fragment, is promoted primarily for tissue repair and recovery.
But again, availability on a peptide website does not equal FDA approval or established clinical efficacy.
FDA reports inadequate safety information regarding proposed compounded thymosin alpha-1 products and says it has not identified human exposure data for compounded TB-500 products sufficient to establish their safety.
So Are Peptides Good or Bad?
Neither.
“Peptide” is a category of molecules, not a diagnosis, treatment plan or guarantee of safety.
Some peptide medications have excellent clinical evidence.
Some are promising investigational therapeutics.
Some have fascinating biological mechanisms but insufficient human trials.
And some are being marketed directly to consumers far ahead of the science.
That distinction is where good medicine comes in.
“But Dr. Scarlett, I Can Buy It Online.”
I know.
That’s actually one of the reasons I’m having this conversation with you.
My patients are intelligent adults. I’m not going to pretend you don’t have access to the internet.
But being able to purchase something doesn’t tell you:
- whether the vial contains what the label says it contains,
- whether the concentration is accurate,
- whether it was manufactured under appropriate sterile conditions,
- whether contaminants or peptide impurities are present,
- whether the compound is appropriate for your medical history,
- or whether anyone knows what repeated long-term exposure will do.
With a drug like retatrutide, the distinction becomes particularly striking: FDA says the substance cannot currently be used in compounding under federal law, yet products bearing its name are still being marketed online.
“Available online” and “medically established” are two very different statements.
Where Chinese Medicine and Functional Medicine Enter the Conversation
This is also where my approach may be somewhat different.
I don’t look at a peptide and ask only:
“What can this drug make the body do?”
I also want to know:
Why isn’t the body doing it well in the first place?
How are you sleeping?
How are you eating?
What does your metabolic health look like?
Are you insulin resistant?
Are you preserving muscle?
How is your digestion?
What is happening hormonally?
What medications are you taking?
What does your inflammatory burden look like?
What does your recovery look like?
And from a Chinese medicine perspective, what larger pattern is this person presenting?
Peptide therapy may sometimes become another tool in the toolbox.
But the tool should never replace understanding the person.
That philosophy sits very comfortably within Yang Sheng, the Chinese medicine tradition of nourishing life.
Our goal isn’t simply to force the body into doing something for the next 12 weeks.
The larger question is:
How do we create the conditions that allow the body to function better for years?
Before You Buy That Peptide…
Ask three questions:
1. Is this compound actually FDA-approved for what I’m trying to treat?
2. What human clinical evidence supports it?
3. Who is responsible for evaluating whether it is appropriate and safe for me?
If the answer to number three is:
“The guy on TikTok told me…”
we probably need to talk.
My Approach
I’m not interested in peptide hype.
And I’m not interested in dismissing a potentially important area of medicine simply because it’s new.
I am interested in the space between those two extremes:
evidence, physiology, appropriate clinical evaluation and informed decision-making.
Some peptides are already legitimate medicines.
Others may eventually become important medicines.
And some may disappear once better clinical research is completed.
Our job is to know the difference.
If you’re curious about peptides—or you’ve already been researching them—bring your questions.
Let’s look at your health, your goals, the evidence and the actual compound you’re considering before deciding whether peptide therapy belongs anywhere in your health plan.
Dr. Scarlett
Red Lotus Wellness Center
Medical Disclaimer
This article is provided for general educational purposes and is not individualized medical advice. Discussion of an investigational or non-FDA-approved compound does not constitute a recommendation, prescription or endorsement of its use. Medication and peptide decisions should be made with an appropriately licensed healthcare professional after consideration of medical history, medications, laboratory findings, potential contraindications and current regulatory status.
Selected References
Jastreboff AM, et al. Triple-Hormone-Receptor Agonist Retatrutide for Obesity—A Phase 2 Trial. New England Journal of Medicine. 2023.
ClinicalTrials.gov. Phase 3 studies of retatrutide (LY3437943), including obesity and cardiovascular-disease populations and comparison with tirzepatide.
U.S. Food and Drug Administration. FDA’s Concerns with Unapproved GLP-1 Drugs Used for Weight Loss. Updated 2026.
U.S. Food and Drug Administration. Certain Bulk Drug Substances for Use in Compounding That May Present Significant Safety Risks.
Dou Y, et al. The potential of GHK as an anti-aging peptide. Biomedical Pharmacotherapy. Review of GHK/GHK-Cu biology and regenerative research.
ClinicalTrials.gov. Topical GHK-Cu Gel for Acute Skin Wound Healing.
