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How do peptides work?

The science, simplified

Stylized illustration of a peptide chain with blue, green, and cream colored beads linked together

Peptides are short chains of amino acids, the building blocks that make up proteins. Many peptides occur naturally in the body, and many work like tiny messengers signaling parts of your body to do specific things.

What makes them interesting to researchers is their specificity. Different peptides interact with different targets in the body, like keys cut for particular locks. That precision is why peptides are an active area of scientific study across a range of biological processes, from hormone signaling to tissue repair.

You’ve probably heard of GLP-1 medications like and . Yes, those are peptides too.

Peptides are a fast-moving and heavily regulated area. Only certain ones are FDA-approved, and many remain investigational. At PreventiveMD, we only offer what’s legally available and our licensed providers can help you understand the options that are right for you and what the evidence does and doesn’t yet show.

Our offerings

Physician-guided care protocols

GLP-1 & Weight Loss

Injection vial of 100% U.S.-compounded Semaglutide from PreventiveMD

Semaglutide

As low as $83 per month, all-in

Injection vial of 100% U.S.-compounded Tirzepatide from PreventiveMD

Tirzepatide

As low as $97 per month, all-in

Bottle of Foundayo (orforglipron) tablets

Foundayo®

$49 per month membership fee +

Bottle of Wegovy (semaglutide) pills

Wegovy®

$49 per month membership fee +

Zepbound (tirzepatide) injection vial

Zepbound®

$49 per month membership fee +

Peptide Therapy

Cream bottle of 100% U.S.-compounded GHK-Cu (GHK-Copper) from PreventiveMD

GHK-Cu

As low as $89 per month, all-in

Injection vial of 100% U.S.-compounded Glutathione from PreventiveMD

Glutathione

As low as $94 per month, all-in

Injection vial of 100% U.S.-compounded NAD+ from PreventiveMD

NAD+

As low as $119 per month, all-in

Injection vial of 100% U.S.-compounded Sermorelin from PreventiveMD

Sermorelin

As low as $119 per month, all-in

Investigational peptides

The future of peptide therapy

Following recent FDA action, several peptides may return to compounding access in the coming months. These are not currently part of our protocols at PreventiveMD. They remain investigational, and we’re watching the FDA’s review process closely.

If and when regulatory guidance allows safe, legitimate access, we’ll carefully evaluate each one before considering it for our patients. For now, we’re sharing this to keep you informed about where the peptide space is heading.

  • Recovery & tissue repair

    • BPC-157Gut, joint, soft tissue
    • TB-500Muscle & tendon recovery
    • PEG-MGFMuscle repair & growth
  • Skin, hair & aesthetics

    • GHK-Cu (injected form)Skin, hair, tissue regeneration
    • Melanotan IISkin pigmentation
  • Metabolic & mitochondrial

    • MOTS-cMitochondrial & metabolic support
  • Sleep & circadian

    • DSIPSleep support
    • EpitalonSleep & circadian rhythm research
  • Cognitive & mood

    • SemaxCognitive & mood research
    • DiHexaCognitive & neurogenesis research
  • Immune & anti-inflammatory

    • KPVAnti-inflammatory & gut health
    • LL-37Antimicrobial & immune support

Anticipated FDA review dates

The following dates reflect the publicly-known review windows for these investigative peptides.

  1. 7 peptides

    • BPC-157
    • TB-500
    • MOTS-c
    • KPV
    • DSIP
    • Semax
    • Epitalon
  2. 5 peptides

    • GHK-Cu (injected form)
    • Melanotan II
    • LL-37
    • DiHexa
    • PEG-MGF

FAQs

In case you were wondering

It depends on the medication. Branded options like Foundayo®, Wegovy®, and Zepbound® are FDA-approved. The rest of the compounded medication we offer are not. They’re prepared individually by state-licensed 503A pharmacies we work with, using FDA-regulated active ingredients and based on a provider’s prescription for a specific patient.

503A compounding is a long-established part of U.S. healthcare, regulated by state pharmacy boards under United States Pharmacopeia (USP) standards.

Thank you for considering us to support you in your health journey. The process is simple and from start to delivery usually takes about a week.

  1. Get started on our site: Complete checkout and a quick medical assessment.
  2. Request review: A licensed provider reviews your assessment, typically within 24-48 hours, and prescribes if appropriate. We currently do asynchronous reviews, meaning there are no live appointments to schedule or wait for. You may chat with your provider for any clarifications.
  3. Pharmacy prepares and ships: Your prescription goes to one of our partner pharmacies, who will process your order for 3-5 business days and ship it cold to your door with 1- or 2-day shipping.

For our compounded medications, yes every dose is the same price, and no, there are no hidden fees. Our pricing is based on your plan length, never your dose, and is designed to be simple and not gimmicky.

Whether you’re on a starting dose or a higher maintenance dose, your price stays the same, and it’s all-inclusive: provider review, medication, supplies, shipping, and ongoing support. There are no membership, consultation, or cancellation fees.

Longer plans come at a lower monthly rate and are paid upfront, and you can always see current pricing for every medication and plan on our site.

You’ll see GLP-1s discussed in two forms: FDA-approved branded products and compounded versions prepared by a licensed compounding pharmacy. Both contain the same active peptide, but they’re not the same product. FDA-approved branded GLP-1s have been reviewed by the FDA for safety, efficacy, and manufacturing quality. Compounded GLP-1s have not been reviewed in the same way, and the rules governing when they can be legally compounded depend on factors like FDA shortage status and clinical need that have shifted considerably over the last year.

At PreventiveMD, we offer branded GLP-1s, as well as compounded semaglutide and tirzepatide where it’s clinically appropriate and currently permitted. Your provider can explain the differences, the trade-offs, and which option fits your situation.

Peptides have been studied for decades and many are well-tolerated when prescribed and dispensed properly. That said, no medication is universally safe — it depends on the specific peptide, the dose, your medical history, and the quality of the source.

That’s why we work exclusively with licensed providers who review your full health profile before prescribing, and with state-licensed 503A pharmacies. If a peptide isn’t right for you, we’ll tell you.

Per official pharmacy guidance:

  • Empower Pharmacy: stable outside refrigeration up to 7 days at 104°F, and up to 3 days at up to 140°F.
  • Boudreaux’s New Drug Store: the medication can remain outside refrigeration for up to 45 days as long as it does not exceed 105°F, and should not appear cloudy when drawn into the syringe.

To prioritize your peace of mind, we’re happy to have the pharmacy’s staff call you to walk through your shipment and your concerns.

No labs are required, and we don't order them, since we're not a full replacement for a primary care provider. However, you're welcome to share any recent labs with your provider on your care portal.

Eligibility isn't decided by any single number: your provider reviews your full medical history and overall health picture, and makes an individual determination.

Common side effects vary by medication. If you experience a concerning reaction, message your care team. They respond within 24 hours, or sooner for urgent symptoms.

For severe reactions (difficulty breathing, swelling, or signs of an allergic response), seek emergency care first, then let us know.

Many peptides sold through unregulated online sources are typically sold outside of FDA oversight and may not be third-party tested. This is distinct from peptides dispensed through compounding pharmacies which operate under federal and/or state regulatory oversight.

A quick note on GHK-Cu specifically: the topical (cream) form of GHK-Cu has long been legal and widely used in cosmetic skincare, and PreventiveMD does offer GHK-Cu cream as part of our skin and hair protocols.

The injectable form of GHK-Cu is the version currently under FDA review and is not something we offer at this time. If you’ve seen GHK-Cu sold online as an injectable, that is the form we’re referring to when we talk about investigational peptides.

We only offer therapies that are either FDA-approved or legally available through licensed compounding pharmacies under appropriate regulatory pathways. Several of these peptides are currently under FDA review (PCAC meetings July 2026 and February 2027). Until that review is complete and proper regulatory clearance is in place, we are not prescribing them.

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