Trial primary endpoint window
The randomized crossover periods were 12 weeks each, with a 4-week washout.
Protocol / Research Dosing Guide
SS-31 Dosage Guide: Elamipretide Trial Evidence, Reconstitution and Safety
An evidence-organized SS-31 reference that keeps the FDA-approved Forzinity label and the TAZPOWER trial separate from research-vial and community reports.
Last reviewed September 16, 202617 minute readResearch information only
Level 5 — Approved in one rare pediatric/adult indicationNo trial in healthy adultsResearch vials are not the approved product
SS-31 Quick Start
SS-31 is a small peptide that concentrates in the inner mitochondrial membrane and binds cardiolipin, the phospholipid scaffold that organizes the electron transport chain. That mechanism is why it is studied in mitochondrial disease. The approved drug, Forzinity, is a ready-to-use 80 mg/mL solution for Barth syndrome. Research-use lyophilized vials sold at 10, 40 or 50 mg are a different, unapproved product, and no published human trial has tested SS-31 in healthy adults for anti-aging or performance purposes.
Why researchers care
Mitochondrial membrane stabilization in genetic and age-related disease models
Class
Synthetic four-amino-acid, mitochondria-targeted, cardiolipin-binding peptide (elamipretide)
Route reported
Subcutaneous injection in both the approved label and the pivotal trial
Cycle length
Continuous daily use in the approved label; no validated healthy-adult cycle
Regulatory status
Approved as Forzinity (elamipretide) for Barth syndrome in patients 30 kg and over; all other uses are investigational
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SS-31 Dosing Protocol and Schedule
The supplied source reports the Forzinity label dose of 40 mg subcutaneously once daily for patients 30 kg and over (20 mg for severe renal impairment), the identical 40 mg SC daily dose used in the TAZPOWER trial, and separate community-reported research-vial ranges clustering from about 1 mg to 20 mg per day. It states plainly that the community ranges are not derived from any controlled trial in healthy adults.
| Phase or study | Amount | Frequency / evidence |
|---|---|---|
| Forzinity label, patients ≥30 kg | 40 mg subcutaneous once daily | FDA label |
| Forzinity label, severe renal impairment | 20 mg subcutaneous once daily | FDA label |
| TAZPOWER trial dose | 40 mg subcutaneous once daily | Human trial |
| Community low-dose reports | 1–5 mg once daily | Community reported |
| Community guide-page range | 5–10 mg once daily | Community reported |
| Community performance-oriented range | 10–20 mg once daily | Community reported |
| Rest period | Not established for research-vial use | Not established |
Every published human dose for SS-31 is 40 mg/day for Barth syndrome, a specific genetic cardiomyopathy. Community milligram ranges are one-eighth to one-half of that figure and have never been tested in a controlled healthy-adult trial, so they cannot be assumed proportionally safe or effective.
SS-31 Supplies Needed
Neutral research-material planning only. This does not establish an appropriate amount or route.
Research planning item
Exact labeled research vial
Research planning item
Bacteriostatic water at a measured volume
Research planning item
U-100 insulin syringes
Research planning item
Alcohol prep swabs
Research planning item
Sharps container
Research planning item
Refrigeration for the prepared vial
Research planning item
Written concentration label with the preparation date
SS-31 Reconstitution Calculator
Vial-format concentration math
Concentration
5 mg/mL
Draw volume
1 mL
U-100 units
100
Mathematical draws
2
Arithmetic only. The entered amount is not a recommendation and does not establish suitability.
Best Time to Take SS-31: Morning or Night?
Morning or evening?
Not established for research-vial use. The label specifies the same time each day without stating morning or evening.
Once daily or split?
Both the label and TAZPOWER used once-daily dosing.
With food?
Not applicable to an injected product.
Missed amount?
The Forzinity label instructs skipping a missed dose and not doubling up; no such instruction exists for research-vial use.
SS-31 Route Comparison
| Format | What is reported | Evidence limit |
|---|---|---|
| Forzinity ready-to-use solution | 280 mg/3.5 mL, 80 mg/mL, single-patient-use | Approved product; not a lyophilized vial and needs no reconstitution |
| Research-use lyophilized vial | 10, 40 or 50 mg, subcutaneous after reconstitution | Not the approved product; no independent human trial of this format |
| Oral | Not viable | Peptide is not orally bioavailable |
| Route conversion | Not established | Research-vial concentration does not map onto the label's ready-to-use strength |
Routes and amounts are not interchangeable unless a verified study explicitly establishes a conversion.
SS-31 Half-Life and Dosing Frequency
| Measure | Finding | Evidence limit |
|---|---|---|
| Human half-life | Not established in the sources reviewed | Do not infer frequency from an unpublished figure |
| Dosing frequency basis | Once daily is the label and trial pattern | Not stated to be pharmacokinetically derived in the source reviewed |
| Renal clearance | Label reduces dose in severe renal impairment | Suggests renal handling but a specific half-life is not established here |
| Community frequency | Once daily is also the common community pattern | Extrapolated from the label, not independently validated |
SS-31 Dosage Chart
| Route | Amount | Frequency | Source | Human validation |
|---|---|---|---|---|
| Subcutaneous (Forzinity label) | 40 mg | Once daily | FDA label / TAZPOWER trial | Approved for Barth syndrome only |
| Subcutaneous (severe renal impairment) | 20 mg | Once daily | FDA label | Approved dose adjustment |
| Subcutaneous (research vial) | 1–5 mg | Once daily | Community report | No |
| Subcutaneous (research vial) | 5–10 mg | Once daily | Community report | No |
| Subcutaneous (research vial) | 10–20 mg | Once daily | Community report | No |
Published study values describe those studies. Community-reported values are not validated dosing recommendations.
SS-31 Reconstitution Guide
Concentration: 5 mg/mL
| Entered amount | Volume | U-100 units |
|---|---|---|
| 5 mg | 1 mL | 100 units |
| 10 mg | 2 mL | 200 units |
- 1.Confirm the exact quantity printed on the research vial label.
- 2.Choose and record the bacteriostatic water volume.
- 3.Clean the stopper with an alcohol swab.
- 4.Add the liquid slowly down the vial wall.
- 5.Swirl gently until clear; never shake.
- 6.Inspect for cloudiness, discoloration or particles and discard anything that is not clear.
- 7.Label the vial with the calculated concentration and preparation date.
- 8.Refrigerate the prepared vial; use only the calculated concentration for arithmetic.
Reconstitution does not establish identity, purity, sterility, stability, or an appropriate amount.
How SS-31 Works
Localization
SS-31 concentrates selectively in the inner mitochondrial membrane rather than distributing generally.
SS-31 Human Trials and FDA Status
Current status · verified September 16, 2026
Approved as Forzinity (elamipretide) for Barth syndrome in patients 30 kg and over; all other uses are investigational
- The TAZPOWER Phase 2/3 randomized, double-blind, placebo-controlled crossover trial (NCT03098797) enrolled 12 male patients ages 12–35 with genetically confirmed Barth syndrome using 40 mg SC daily.
- During the 12-week randomized crossover period, elamipretide did not reach statistical significance versus placebo on the two co-primary endpoints.
- In the open-label extension running up to 168 weeks, six-minute walk distance improved by a cumulative 96.1 meters at week 168, and knee extensor muscle strength improved, the endpoint cited for accelerated approval.
- No published human trial has tested SS-31 in healthy adults for anti-aging, athletic performance, or general mitochondrial support.
Who Should Avoid SS-31?
This is an evidence-gap and precaution list, not an approved prescribing label.
Anyone without genetically confirmed Barth syndrome seeking the label dose
The approved indication is specific and narrow
Pregnancy or breastfeeding
No safety data outside the approved population
Patients under 30 kg
Safety and effectiveness not established per label
Severe renal impairment without dose adjustment
Label requires a reduced dose in this group
Concurrent medicines without clinician review
No broad interaction dataset for research-vial use
Long-term unsupervised research-vial use
No safety data outside the approved product and trial population
SS-31 Side Effects, Risks and Safety
Injection-site reactionsReported in label and trial context
Important limitation: Most commonly described adverse finding.
Gastrointestinal symptomsReported in trial context
Important limitation: Reported at low frequency in Barth syndrome trial population.
Effects in healthy adultsUnknown
Important limitation: No controlled healthy-adult safety dataset.
Long-term research-vial safetyUnknown
Important limitation: No independent safety data for the unapproved format.
Drug interactionsUnknown
Important limitation: No interaction studies outside the approved label population.
Renal handlingConsidered in label dosing
Important limitation: Dose reduced in severe renal impairment.
SS-31 Timeline and Monitoring
Open-label extension
Walk-distance and strength changes were reported out to 168 weeks.
Research-vial timeline
Not established; no controlled study defines an onset or peak-effect window outside Barth syndrome.
Monitoring focus
Injection-site condition and any change relevant to the reason a clinician is involved.
SS-31 Benefits and Results: What the Evidence Shows
| Claim | Evidence level | What research shows | Important limitation |
|---|---|---|---|
| Knee extensor muscle strength in Barth syndrome | Human trial (open-label extension) | TAZPOWER extension data | Approved population only |
| Six-minute walk distance in Barth syndrome | Human trial | Did not reach significance in randomized crossover; improved in open-label extension | Approved population only |
| Mitochondrial support in healthy adults | Not established | Extrapolated from mechanism and disease-model data | No controlled human trial |
| Anti-aging or performance effects | Not established | Community claim | No human trial support |
SS-31 Storage and Handling
Forzinity ready-to-use vial
Follow the FDA label; discarded after 8 days once first used, per label.
Research-use lyophilized powder
No independent stability study was identified; follow the exact product label.
Prepared research vial
Refrigerate; no validated research-vial stability duration was identified.
Appearance
A clear, colorless solution is expected; cloudiness, discoloration or particles mean discard.
SS-31 Troubleshooting
Solution appears cloudy
Discard; a cloudy or particle-containing solution should not be used.
Confusing label dose with research-vial dose
These are different products at different strengths; do not treat one as validating the other.
Calculated units look wrong
Recheck vial quantity, diluent volume, target amount, and syringe conversion.
Unexpected symptoms occur
No research-vial safety protocol exists outside the approved label population; seek licensed clinical review.
A scheduled amount is missed
The Forzinity label says skip and resume; no such instruction exists for research-vial use.
SS-31 Comparisons
| Compound | Class or mechanism | Evidence | FDA status |
|---|---|---|---|
| SS-31 / Forzinity | Cardiolipin-binding mitochondrial peptide | Approved for Barth syndrome only | 40 mg/day label and trial dose |
| MOTS-c | Mitochondrial-derived peptide research interest | Primarily preclinical | No FDA approval |
| NAD+ precursors | Metabolic cofactor research interest | Mixed human evidence depending on the specific molecule | No FDA approval for anti-aging use |
SS-31 Frequently Asked Questions
What is SS-31?
A synthetic four-amino-acid peptide that binds cardiolipin in the inner mitochondrial membrane; the generic drug name is elamipretide.
Is SS-31 FDA approved?
Yes, as Forzinity, for improving muscle strength in Barth syndrome patients 30 kg and over.
Are research-vial SS-31 products the same as Forzinity?
No. They are lyophilized, unapproved research products at different strengths and are not interchangeable with the label.
What dose did the pivotal trial use?
40 mg subcutaneously once daily, the same dose now on the Forzinity label.
Is there a healthy-adult dosing trial?
No published human trial has tested SS-31 in healthy adults.
What is its half-life?
Not established in the sources reviewed.
Did the trial meet its main goals?
Not in the 12-week randomized crossover; six-minute walk distance and muscle strength improved later in the open-label extension.
What side effects are documented?
Injection-site reactions and gastrointestinal symptoms are reported in the Barth syndrome trial and label population.
Is there a validated missed-dose rule for research vials?
No. The label's skip-and-resume instruction applies to Forzinity, not to research-vial use.
What does the calculator do?
It converts entered vial and liquid values into concentration and syringe-volume arithmetic only.
Is long-term safety known outside Barth syndrome?
No.
Sources and Research
Regulatory
1. FORZINITY (elamipretide) injection prescribing information
FDA-approved label, initial approval 2025, for Barth syndrome patients ≥30 kg.
Open direct sourceHuman research
2. TAZPOWER: elamipretide in Barth syndrome
Randomized, double-blind, placebo-controlled crossover trial with open-label extension.
Open direct sourceHuman research
3. Elamipretide for Barth syndrome: 168-week open-label extension results
Reports the cumulative six-minute walk distance and strength findings.
Open direct sourceCoverage source
4. SS-31 protocol coverage source
Community research-vial ranges and label summaries; not primary evidence.
Open direct sourceMissing information flagged for review
- Healthy-adult dosing trial: Not established
- Human pharmacokinetics and half-life outside the approved label context: Not established
- Research-vial-specific stability and safety data: Not established
- Validated research-use cycle and rest period: Not established
- Drug interaction data outside the approved label population: Not established