Elamipretide
Approved only for Barth syndrome; untested for energy or anti-aging.
Four amino acids that lodge in the inner membrane of mitochondria and steady a fat molecule called cardiolipin. In 2025 it won its first approval, for one ultra-rare disease. Online it is sold as SS-31 for energy and anti-aging. A made by Stealth BioTherapeutics, also called SS-31, Forzinity and Bendavia.
What the evidence shows
Side effects and risks
Who should avoid it: Newborns (the product contains benzyl alcohol), and anyone buying SS-31 online for energy.
How it works
- Where it acts
- Cardiolipin, a fat molecule in the inner membrane of mitochondria.
- What it changes
- It steadies the machinery that makes the cell's energy.
- What people notice
- In Barth syndrome, gains in knee muscle strength in an open-label extension, though the short controlled trial missed its main goals. Injection-site reactions are very common.
How it is taken
A 40 mg injection under the skin once a day, or 20 mg with severely reduced kidney function.
Getting it in the United States
The legal route for Elamipretide
Get a prescription from a licensed clinician. Fill it at a licensed pharmacy or through the maker's own direct service.
Single specialty pharmacy
Commercially available since late 2025 through one exclusive specialty pharmacy, with a company support programme for cover and injection training. Insurers are expected to approve only confirmed Barth patients of at least 30 kg.
Source: UMDF Forzinity page, 2025-12
Expanded access programme
Before approval nearly a fifth of US Barth patients got it through expanded access. The company agreed to keep supplying under-30 kg children already treated or in emergencies, described as a stopgap.
Routes people use for any peptide in the United States
Telehealth prescribing
Online clinics prescribe after a questionnaire, sometimes with no live doctor visit, and mail the drug. FDA moved in February 2026 to restrict mass-marketed compounded copies and claims that they are generic equivalents.
Risk: Thin medical screening. Compounded versions are not reviewed by FDA for quality.
Covers: Approved GLP-1 drugs, compounded semaglutide and tirzepatide
Source: GZERO Media, Apr 2026
Clinical trial enrolment
The only lawful way to get an unapproved peptide drug with medical monitoring. ClinicalTrials.gov lists eligibility, sites and phone numbers. Researchers note recruitment is hard when people can buy the drug on the gray market instead of risking placebo.
Risk: Possible placebo assignment, strict eligibility and travel to a study site.
Covers: Investigational peptide drugs still in development
Source: NIH, finding a clinical trial
Routes people use for any peptide in the United States
Compounding pharmacy with prescription
A clinician prescribes and a pharmacy compounds. Twelve peptides left the FDA do-not-compound category in April 2026 and a panel backed six in July, but they are not yet formally eligible. Pharmaceutical-grade ingredient is scarce.
Risk: Legal status is unsettled until FDA rulemaking ends. Pharmacies may use research-grade ingredient.
Covers: BPC-157, TB-500, KPV, MOTS-c, Semax, Epitalon and similar
Source: Frier Levitt, Apr 2026
Med spas and weight-loss clinics
Very common. Secret shoppers called 75 clinics and med spas in two states after shortages ended. 92 percent offered compounded semaglutide and 87 percent tirzepatide, often mixed with B vitamins to look custom.
Risk: Four of 23 suppliers lacked sterile compounding licenses and four had disciplinary records.
Covers: Compounded semaglutide and tirzepatide
Source: American Med Spa Association on JAMA Health Forum study, Jul 2026
Concierge and longevity doctors
Cash-pay physicians build peptide plans for wealthy clients. Reporting from San Francisco says some source from overseas channels, domestic research-use-only sellers or the few compounding pharmacies that will supply clinicians.
Risk: A doctor's involvement does not guarantee a pharmaceutical-grade product.
Covers: BPC-157, thymosin alpha-1, Selank, Semax, CJC-1295, ipamorelin, retatrutide
Source: San Francisco Standard, Sep 2025
Cross-border purchase or import
FDA says importing drugs for personal use is illegal in most cases but it may not object to small personal quantities in limited situations. Reporting also describes people travelling to Mexico for injections.
Risk: Packages can be seized. Product origin and cold-chain handling are hard to check.
Covers: Approved prescription peptides sold abroad
Source: FDA, personal importation
Routes people use for any peptide in the United States
Research-chemical websites
Sites sell vials marked for research or not for human consumption, with no prescription. FDA says some ship direct to consumers with dosing directions, and it has sent warning letters. Retatrutide exists only through this route or trials.
Risk: Unknown identity, strength and sterility. No pharmacist or prescriber involved.
Covers: Retatrutide, semaglutide, tirzepatide, BPC-157 and most unapproved peptides
Source: FDA, unapproved GLP-1 drugs page
Direct orders from Chinese factories
Buyers message factory sales agents and pay by crypto or payment app. A minimum order of about ten vials pushes people to buy in bulk and share. A blockchain analysis found US buyers were the largest source of funds.
Risk: Many of the same vendors list fentanyl precursors. Lab reports sent by sellers cannot be verified.
Covers: GLP-1 copies, melanotan II, BPC-157, TB-500, GHK-Cu, epitalon
Source: TRM Labs, Oct 2026
Chat groups and social sellers
Dealers are found through Telegram, WhatsApp, Discord and influencer discount codes. In a May 2026 survey of 1,000 US users, 14.5 percent bought this way and three quarters asked an AI chatbot for dosing.
Risk: 45 percent of social media buyers in that survey reported an emergency or urgent care visit for a reaction.
Covers: Retatrutide and other research-use-only peptides
Source: The Ethos, May 2026
This describes what people do. It is not advice. The decision is yours.
What users report
Recurring themes in public forum posts, unverified and with no comparison group.
Reported benefits
- More stamina, say gray-market users
Reported problems
- Sore, itchy injection sites
- Cost
Based on very few reports.
More contextCase reports, what public figures say, videos and articles, when options run out and the chemistry
Case reports
From journals, regulators and studies of users. One case proves little.
Benefit reportedtrial result in rare group - 2025
The patient foundation reported that most people from the original Barth trial were still on the drug more than eight years later. It cited gains of about 45 percent in muscle strength and 40 percent in heart function.
Source: Barth Syndrome Foundation via Business Wire, 2025-04
No effecttrial result in rare group - 218 people - 2023
In adults with primary mitochondrial myopathy, six months of treatment did not beat placebo on six-minute walk distance or fatigue score. The drug was well tolerated.
Source: Institut de Myologie, 2023
Mixed resulttrial result in rare group - 2024
A post hoc look at the same trial found patients with replisome gene defects and eye muscle weakness walked about 45 metres further than placebo. The wider replisome group result missed significance.
What experts and influencers say
Paraphrased from the linked sources.
Called the FDA's 2025 refusal and extra delay unconscionable. Said the proposed route left out the sickest infants and pointed to petitions signed by nearly 20,000 people and over 50 clinicians.
Emily MilliganWebsiteRecommends
Photo source: barthsyndrome.org
Judges each peptide separately. He sees no use case for BPC-157: no human evidence, animal data mostly from one lab, and claims that keep widening. He is not a proponent of growth-hormone peptides such as CJC-1295, citing short studies and no long-term safety data. He says elamipretide makes sense only for Barth syndrome, that the risks of melanotan II probably outweigh a cosmetic tan, and that he stopped prescribing bremelanotide. He regards the GLP-1 drugs as clearly effective.
Peter AttiaInstagramMixed view
After approval, credited generations of patients and families who joined trials, lobbied legislators and funded research for a result she said had once seemed out of reach.
Kristen CliffordWebsiteRecommends
Photo source: prweb.com
Announced accelerated approval for patients of at least 30 kg based on knee muscle strength, a measure that predicts but does not prove benefit. A placebo-controlled confirmatory trial is required.
Source: FDA press release, 2025-09
George TidmarshWikipediaMixed view
After the 2025 rejection, said the FDA's accelerated-approval suggestion offered a way forward and urged fast access for newborns. The company cut 30 percent of staff to fund the refiling.
Reenie McCarthySourceRecommends
Money: Chief executive of the developer
Their post hoc analysis found a walking signal only in patients with certain nuclear gene defects. They called it hypothesis-generating and the basis for the follow-up NuPOWER trial.
MMPOWER-3 Trial InvestigatorsSourceMixed view
Summarised the 218-adult MMPOWER-3 trial in primary mitochondrial myopathy. The drug was well tolerated but did not improve walking distance or fatigue compared with placebo.
Source: Institut de Myologie, 2023
Institut de MyologieSourceWarns against
Told the public not to inject peptides bought online. Said unauthorized products are illegal, unproven and may cause organ damage, clots or tumour growth. A research-use-only label does not make them legal.
Source: Health Canada advisory, 2026-04
Health CanadaSourceWarns against
Watch and read
Explainers, reporting and podcasts worth your time. Summaries are ours. No sellers.
FDA greenlights Stealth Bio's injection as 1st treatment for Barth syndrome
Gabrielle Masson, reporter
Reports the accelerated approval of elamipretide (Forzinity) for Barth syndrome, based on muscle strength, after earlier rejections, with a confirmatory trial still required.
Concise account of a rocky approval.
Stealth Bio's Forzinity finally approved as first Barth syndrome therapy
Robert Barrie, reporter
Explains the approval and its evidence limits: the supporting strength gain came from an open-label trial portion, so patient benefit is not yet directly shown.
Spells out the evidence gaps behind the approval.
When options run out
Uses people turn to when standard treatment has failed.
Infants in acute heart failure
- Who
- Families of babies with Barth syndrome in cardiac crisis. More than half of deaths occur in the first few years of life.
- Evidence
- No controlled data. The foundation says many infants got it through FDA-cleared emergency requests. The FDA judged pre-approval studies in this group infeasible.
- Route
- FDA emergency access requests
Barth children under 30 kg
- Who
- Small children excluded from the 2025 label, whom insurers are expected not to cover.
- Evidence
- Label rests on strength data in heavier patients. The company says it is gathering data to extend the label to all ages.
- Route
- Company expanded access for existing and emergency patients
Source: UMDF Forzinity page, 2025-12
Primary mitochondrial myopathy, off label
- Who
- Adults with other mitochondrial diseases and no approved drug, especially those with nuclear gene defects.
- Evidence
- The main phase 3 trial failed. A subgroup signal is being tested in the NuPOWER trial. Off-label prescribing is possible but insurers may refuse.
- Route
- NuPOWER phase 3 trial
Source: UMDF Forzinity page, 2025-12
Legal last-resort routes
Expanded access (compassionate use)
For a serious or life-threatening condition with no comparable alternative and no trial you can join. Your physician asks the company for the drug, then files with FDA and an ethics board. The company can refuse. Costs are often not insured.
Right to Try
For a life-threatening condition after approved options are exhausted and no trial is open to you. The drug must have finished Phase 1 and be in active development. Your doctor asks the manufacturer directly. FDA does not review requests.
Source: FDA, Right to Try
Trial finders
Search ClinicalTrials.gov by condition or drug name, check eligibility and call the listed site. ResearchMatch is a free NIH-funded registry that lets researchers find you. Discuss risks with your own clinician before enrolling.
Source: NIH, finding a clinical trial
Personal import for serious conditions
FDA may not object when a US citizen imports up to about three months of a drug for a serious condition with no effective US treatment, with written personal-use confirmation and a US doctor's details. It is discretion, not a right.
Source: FDA, personal importation
Patient-specific compounding
When the approved product cannot meet a specific need of an identified patient, a prescriber can order a compounded version from a licensed pharmacy. Lower price alone does not qualify. Ingredients must be pharmaceutical grade.
Amino-acid sequence
Striped tiles are mirror-image (D) amino acids, which resist breakdown. Ringed tiles are amino acids not found in natural proteins.
Questions people ask
What is elamipretide approved for?
Muscle strength in Barth syndrome, sold as Forzinity for patients weighing at least 30 kg. It received US accelerated approval in September 2025; the 12-patient trial missed its main goals, and approval rests on knee strength gained in an open-label extension.
Does SS-31 work for energy or anti-aging?
This has not been studied in healthy people. Gray-market users report more stamina, but those reports are very few.
What are the side effects of elamipretide?
Injection-site reactions occurred in every patient in the trial, and allergic reactions have occurred. It has been tested in very few people.
Is SS-31 legal?
In the US it is approved only as Forzinity for Barth syndrome, and FDA named SS-31 in warning letters to research-use-only sellers in August 2026. No EU authorization or UK license was found.
Your notebook
Taking it? A ten-second daily check-in keeps a record of how you feel, to talk through with your clinician.
Sources
- Forzinity US prescribing information (DailyMed)
- Stealth BioTherapeutics: pipeline update (6 Jan 2026)
- Mighty Therapeutics: confirmatory study begins (8 Jul 2026)
Structure: PubChem