SS-31 40mg Pen

This is the ProPeptide-labelled SS-31 40mg pen. It contains the same molecule Remy Research stocks as a freeze-dried vial, already in solution: 40mg in a 3mL cartridge (about 13.3mg per mL) inside a pen-style housing.

SS-31 is a four-residue synthetic peptide, D-Arg-Dmt-Lys-Phe-NH₂, where Dmt stands for 2′,6′-dimethyltyrosine. Cornell researchers Hazel Szeto and Peter Schiller designed it, and their surnames gave the series its "SS" prefix. Papers also call it elamipretide; older reports use Bendavia or MTP-131.

One point needs to be clear. On September 19, 2025, the FDA granted accelerated approval to Forzinity (elamipretide HCl), a medicine for Barth syndrome. This pen is not that medicine, and the approval does not extend to it. Remy Research supplies it to laboratories as bench material. For research use only. Not for human or veterinary use.

Read the complete literature review in our SS-31 research profile.

Both ProPeptide SS-31 products carry the same tetrapeptide. What differs is the physical form, the quantity and the handling.

A liquid fill instead of a dry powder

The SS-31 vial is lyophilised, so a lab prepares its own solution at the strength its assay needs. The pen arrives as a ready-made solution at a fixed strength. Teams that want one sealed container per experiment series tend to choose the cartridge; teams that need a custom concentration, or the longer shelf life of dry peptide, usually prefer the vial.

More material in one unit

One pen holds 40mg. For long-running studies, a single larger unit can simplify stock records compared with tracking several smaller vials.

Solutions need tighter cold storage

Peptides in solution generally tolerate heat, light and freezing less well than freeze-dried peptide. Refrigerate the cartridge at 2–8°C straight from the parcel, store it boxed and shaded, and never let it freeze. Our peptide stability and storage guide explains why.

Purity specification and batch evidence

ProPeptide specifies this pen at ≥99% purity. To date, no batch-specific report for the SS-31 pen has been published, and this page does not claim otherwise. Tested batches appear in our lab results library, each checkable against the laboratory's own record.

Chilled courier delivery across the UAE

Orders go by cold-chain courier, in insulated packs rated for 2 to 8°C. Inside Dubai, anything ordered before 4 PM is with you that day, typically inside four hours; for the other six emirates, ordering by 12 PM (noon) means next-day delivery.

Most mechanistic data come from isolated mitochondria, cultured cells and animal models. These are research findings, not effects established in people.

Anchoring to cardiolipin

Cardiolipin makes up roughly a fifth of the lipid in the inner mitochondrial membrane and is almost absent elsewhere; it helps hold the curved cristae in shape. A 2013 study by Birk and colleagues, using NMR spectroscopy and fluorescence displacement, described SS-31 binding it in two ways: its two positively charged residues are drawn to cardiolipin's anionic phosphate groups, while the aromatic Dmt and Phe side chains slip into the lipid tails. Cell studies report the peptide gathering at the inner membrane at around 100 times its cytosolic level.

Supporting the respiratory chain's scaffold

The electron transport complexes and ATP synthase are arranged on that cardiolipin framework. Under oxidative stress, isolated mitochondria treated with SS-31 were reported to keep complex activity and membrane potential nearer to unstressed controls. Rat and pig models of ischaemia followed by restored blood flow also reported smaller infarcts.

Muscle energetics in ageing models

In aged mice, a 2013 study reported muscle ATP production and fatigue resistance moving back toward young levels after SS-31, with no change in young muscle. A small 2021 human trial in 39 older adults (Roshanravan et al., PLOS ONE) found a borderline rise in muscle ATP capacity right after one infusion, which had gone by day 7.

Barth syndrome and the limits of the evidence

The TAZPOWER phase 2/3 trial in Barth syndrome, a cardiolipin-remodelling disorder, missed both blinded primary endpoints, then reported a 95.9-metre gain in six-minute walk distance among the eight participants who reached week 36 of the open-label extension. Human data for SS-31 remain small and indication-specific.