You’ve probably seen peptides in skincare and cosmetic products that promise to smoothen and tone the skin, or in supplements with purported benefits like improved bone health, muscle recovery, or boosting metabolism. But those are just a few of the many ways you can buy peptides—short chains of amino acids, the building blocks of proteins—that have become the hot topic of conversations across weight rooms, skincare newsletters, and biohacking forums. These largely unregulated compounds are said to address a host of problems, including hair loss, joint pain, and aging, but most are best known for their ability to boost testosterone levels, increase libido, or give you that “wow” look by promoting more youthful and energizing muscles.

Unlike pharmaceutical drugs, peptides aren’t subject to the same rigorous testing and manufacturing standards as approved pharmaceutical-grade active ingredients. They’re also not cheap: While you can find discounts and loyalty programs to help you save money, the best peptides are the ones that were designed with clinical trials and scientific evidence in mind, meaning they’re often the most expensive. Luckily, you can still get the real deal if you know what to look for.

To avoid getting ripped off, you should be able to easily find information on a company’s website about its manufacturing and verification processes. If the information is hard to find or vague, that’s a red flag that they’re not using the highest quality products. You should also be able to tell if they’re sourcing their products from legitimate suppliers or manufacturers by examining the ingredient list: If you see things such as added sugar, artificial colors, or flavors, move on.

Peptide injections should always be administered under medical supervision. Some injectable peptides are not FDA-approved and may be dangerous if not properly administered. For example, despite its popularity in the bodybuilding community, BPC-157 is on the WADA’s Prohibited List and should not be administered without a physician’s approval. Other peptides, such as growth hormone secretagogues and libido boosters, may cause unwanted side effects.

In fact, a doctor who prescribes unapproved peptides opens themselves up to liability if an adverse event occurs, and this can be extremely costly for pharmacies that are found to have distributed them.

While the peptide market is growing rapidly, researchers are only just beginning to understand how they work. For instance, the body’s digestive enzymes can render many of these substances biologically inactive, or break them down completely before they can enter your bloodstream. Moreover, the effects of these compounds on a person’s metabolism can vary greatly from one individual to another.

That’s why it’s essential to make sure that you only buy peptides from a trusted and approved vendor. The most reputable vendors are going to use clinical-grade ingredients and adhere to strict quality control standards, so you can rest assured that you’re getting the real deal. If you have a physician who’s familiar with peptide therapy, that’s the way to go, but if you don’t, here is a list of physicians who do. buy peptides