PE 22-28 vs SS-31
Updated July 27, 2026 · Reviewed by the PeptidesDB Editorial team
A data-driven comparison of PE 22-28 and SS-31 (also searched as SS-31 vs PE 22-28) — effect profiles, evidence, side effects, and which suits weight loss, muscle, or healing goals.
Verdict
PE 22-28 centers on metabolic, while SS-31 leans toward inflammation. On indexed research, SS-31 is ahead (PE 22-28: 17 studies, Human evidence; SS-31: 19, Human evidence). Choose by goal — and read the primary studies. This is research information, not medical advice.
Key takeaways
- •PE 22-28 is strongest for metabolic; SS-31 for inflammation.
- •Evidence: PE 22-28 Human evidence (17 studies) vs SS-31 Human evidence (19).
- •Both are research-use compounds — not FDA-approved.
Effect profiles, overlaid
At a glance
PE 22-28 vs SS-31: side-by-side
| Metric | PE 22-28 | SS-31 |
|---|---|---|
| Class | Cognitive | Longevity |
| Regulatory status | Research use only | Research use only |
| Evidence grade | Human evidence | Human evidence |
| Studies indexed | 17 | 19 |
| Research level | Emerging | Well Studied |
| Strongest effect | Metabolic & appetite | Inflammation & immune |
| Healing & recovery | 2.0 | 3.0▲ |
| Muscle & body comp | 0.0 | 2.0▲ |
| Metabolic & appetite | 4.0▲ | 4.0▲ |
| Neuro & mood | 0.0 | 3.0▲ |
| Sleep & circadian | 0.0 | 1.0▲ |
| Inflammation & immune | 3.0 | 4.0▲ |
| Skin & aesthetics | 0.0 | 0.0 |
▲ marks the higher AI-assigned effect score (0–5, describing where the literature concentrates — not clinical efficacy).
Mechanism & pharmacokinetics
| Property | PE 22-28 | SS-31 |
|---|---|---|
| Mechanism | — | Targets inner mitochondrial membrane to enhance function and reduce ROS |
| Route | — | Subcutaneous injection |
Established pharmacology — curated for well-characterized compounds and AI-summarized otherwise. A blank (—) means no reliable single value is published (half-life figures for some peptides genuinely disagree across sources). Verify against primary sources such as FDA labels and ClinicalTrials.gov.
What is PE 22-28?
### Summary PE 22-28 is a peptide that has garnered attention in various research contexts, particularly in relation to vascular health and metabolic conditions. Its potential implications in gestational diabetes and placental function are areas of ongoing investigation.
Full PE 22-28 profile, mechanism & studies →What is SS-31?
### Summary SS-31, also known as Elamipretide, is a peptide that has garnered attention for its potential role in mitochondrial protection and its implications in various health conditions, particularly those involving oxidative stress and mitochondrial dysfunction.
Full SS-31 profile, mechanism & studies →Which is better for your goal?
| Goal | Better fit | Why |
|---|---|---|
| Healing | SS-31 | 3.0/5 effect signal |
| Muscle | SS-31 | 2.0/5 effect signal |
| Metabolic | Even | Both ~4.0/5 |
| Neuro | SS-31 | 3.0/5 effect signal |
| Sleep | SS-31 | 1.0/5 effect signal |
| Inflammation | SS-31 | 4.0/5 effect signal |
Fit reflects community-perceived effect profiles — not head-to-head trials. Read each peptide's studies before deciding.
Can you stack PE 22-28 and SS-31?
People sometimes combine peptides that target different pathways, but there is little controlled research on this specific pairing and the interactions aren't well characterized. Because neither compound is FDA-approved, we don't publish stacking or dosing protocols here. Any combination should be discussed with a qualified clinician.
PE 22-28 vs SS-31: side effects
No community-reported effects logged yet.
No community-reported effects logged yet.
Anonymous community reports (count = number of reports), not clinical incidence rates.
What the research says
PE 22-28 has 17 approved studies indexed (Human evidence), and SS-31 has 19 (Human evidence). The Librarian re-checks PubMed, Europe PMC and ClinicalTrials daily, so these counts move. Open each profile to read the summaries and sources.
Frequently asked questions
Is PE 22-28 or SS-31 better?
It depends on your goal. PE 22-28 is strongest for metabolic; SS-31 for inflammation. SS-31 has more indexed studies (19). See the goal-by-goal breakdown above.
Is PE 22-28 or SS-31 better for weight loss?
They score similarly on the metabolic/appetite axis in the community data.
Is PE 22-28 or SS-31 better for muscle?
SS-31 leads on the muscle & body-composition axis (2.0/5).
Which has more research, PE 22-28 or SS-31?
PE 22-28 has 17 approved studies indexed (Human evidence); SS-31 has 19 (Human evidence). Higher counts mean more to read, not proven superiority.
Can you stack PE 22-28 and SS-31?
Some users combine peptides, but there's little controlled data on this specific pairing, and interactions aren't well characterized. We don't publish stacking protocols for compounds that aren't FDA-approved. Discuss any combination with a qualified clinician.
What are the side effects of PE 22-28 vs SS-31?
PE 22-28: no community-reported effects logged yet. SS-31: none logged yet. These are anonymous reports, not incidence rates — see each profile.
Is PE 22-28 or SS-31 FDA-approved?
PE 22-28 is a research-use compound and is not FDA-approved. SS-31 is not FDA-approved. Research-use status is not a legal clearance to compound or use in humans.
Is SS-31 better than PE 22-28?
For inflammation, SS-31 has the edge; for metabolic, PE 22-28 does. Neither is universally "better" — it's goal-dependent, and both should be weighed against their evidence base above.
Comparing related peptides
Regulatory & legal status
PE 22-28 and SS-31 are research-use compounds and are not FDA-approved for human use. FDA approval and compounding rules for peptides change frequently, and research-use status is not a legal clearance for human use. The FDA does not review compounded drugs for safety, effectiveness, or quality. Verify current status with primary sources before acting. Last reviewed July 27, 2026.