Fridays Peptides: The GLP-1 Compounds Behind the Program

This article is part of the PlexusDx Education Hub, where we publish evidence-based guidance on GLP-1 therapies, weight management protocols, and the genetic factors behind every metabolic decision. Browse all Peptides & GLP-1 education

This editorial review gives an overview of the peptides behind Fridays GLP-1 program, how the compounded model works, and the pathway biology a prescription leaves out. Fair-balance editorial framing, not a buying recommendation. As of April 2026.

Full head-to-head: PlexusDx vs Fridays →

This is an independent editorial review. PlexusDx holds no commercial relationship with Fridays, earns no affiliate commission, and was not compensated to publish it.

The peptide category behind GLP-1 programs

GLP-1 therapies are peptides: short chains of amino acids that act on specific receptors. In weight management the two that matter most are semaglutide, a GLP-1 receptor agonist, and tirzepatide, a dual GIP and GLP-1 receptor agonist. Fridays (Fridays Health) works within this category through a telehealth-plus-compounding model, with details published at Fridays' own website.

What Fridays offers in the peptide and GLP-1 space

A licensed provider reviews an online intake covering weight, history, and current medications, and, if you qualify, issues a prescription. That prescription is filled at a retail pharmacy for an FDA-approved brand product or at a 503A compounding pharmacy for compounded semaglutide or tirzepatide, followed by clinical follow-up for titration and side-effect support.

Injection and oral formats

These peptides appear in both injectable and oral formulations. The format affects convenience and dosing schedule, but the underlying pathway biology, and the receptors involved, remains the same. Which format a program emphasizes is often a matter of patient preference and pharmacy capability rather than a difference in the peptide class itself.

Compounded peptides and the 503A pathway

Compounded peptides reach patients through 503A pharmacies, which prepare a medication for a named patient under prescription. This is a recognized, regulated route distinct from FDA-approved brand manufacturing. Understanding the pathway helps you evaluate whether a peptide is being dispensed with appropriate oversight rather than sold casually, and it is the same regulated route PlexusDx uses for its own compounded protocols.

How research frames these peptides

The clinical picture draws on the STEP program for semaglutide (published in The New England Journal of Medicine, 2021) and the SURMOUNT and SURMOUNT-OSA programs for tirzepatide (NEJM 2022 and 2024). Trial populations and endpoints vary, and individual outcomes vary as well, which is why context matters more than headline numbers.

The peptide biology a program overlooks

GLP-1 medications are peptides, and peptides act on receptors and pathways that vary from person to person. Variants in GLP1R, the receptor these peptides target, and in FTO, the fat-mass and obesity-associated gene, map the terrain a peptide protocol operates on. They never predict response to any peptide, but they add pathway context a prescription alone lacks. The Precision Peptide Genetic Test analyzes 14 pathways, 49 peptides, 150+ genetic insights, including FTO, MC4R, and TCF7L2.

PlexusDx peptide and genetic testing approach

PlexusDx offers GLP-1 peptides through its Weight Management Protocols, including Semaglutide Injection and Tirzepatide Injection, and leads upstream with the Precision Peptide Genetic Test.

No affiliation: PlexusDx is independent of Fridays and has no commercial ties to the brands discussed in this review.

More from the PlexusDx library: GLP-1 Receptor Agonist, What Is GLP-1.

Disclaimer: this article is educational. PlexusDx is not affiliated with Fridays and has no commercial relationship with the brands reviewed. PlexusDx offers semaglutide and tirzepatide through its own Weight Management Protocols, and this piece compares approaches within the GLP-1 telehealth space. The Precision Peptide Genetic Test analyzes how your genes influence peptide-related biological pathways; it does not predict response to any specific medication and is not a pharmacogenomic test. Speak with a qualified healthcare provider before beginning any peptide protocol.

Frequently Asked Questions About Fridays Peptides

What peptides does Fridays work with?

Fridays operates in the GLP-1 space, where the relevant peptides are semaglutide, a GLP-1 receptor agonist, and tirzepatide, a dual GIP and GLP-1 receptor agonist. These are dispensed as compounded products through a 503A pharmacy after a clinician reviews your intake and issues a prescription.

Are compounded peptides safe and legal?

Compounded semaglutide and tirzepatide are prepared by 503A pharmacies for individual patients under a valid prescription, a recognized regulated pathway. Safety depends on proper licensure and clinical oversight, which you can verify through state pharmacy boards and by confirming a provider reviews each case before prescribing.

How much do peptide programs like Fridays cost?

On its pricing page (joinfridays.com/pricing, verified 2026-07-20), Fridays lists compounded semaglutide at $249 and tirzepatide at $359 monthly month-to-month, with $0 membership and free shipping. Annual prepay lowers the equivalent, and rates moved within a single day, so confirm the live figure.

Does the genetic test analyze peptides directly?

It analyzes the genes and pathways behind peptide biology, not the peptides themselves, and it never predicts drug response. The Precision Peptide Genetic Test reads variants such as FTO across pathways to describe your baseline before you consider any peptide protocol with a provider.

This article is part of the PlexusDx Education Hub. Browse all Peptides & GLP-1 education