Side-by-side · Research reference
PE 22-28vsSNAP-8
Side-by-side comparison across mechanism, dosage, evidence, side effects, administration, and stack synergies. Citations on every claim where available.
AAnimal-StrongHUMAN-REVIEWED16/47 cited
BHuman-MechanisticHUMAN-REVIEWED8/46 cited
PE 22-28
TREK-1 Antagonist · Pre-Clinical
IP · SQ · Once Daily (animal models)Djillani 2017Pietri 2019
SNAP-8
Synthetic Octapeptide · Cosmetic Topical
TopicalRoute
8-AAPeptide length
SNAREPrimary target
Topical · Facial application · Twice daily
01Mechanism of Action
Parameter
PE 22-28
SNAP-8
Primary target
TREK-1 two-pore-domain potassium channelDjillani 2017Ma 2020
SNARE complex (SNAP-25 competitive binding site)
Pathway
TREK-1 channel blockade → Neuronal membrane depolarisation → Enhanced hippocampal excitability → Increased neuroplasticity
Acetyl octapeptide-3 → SNARE complex disruption → Reduced vesicular fusion → Decreased acetylcholine release → Muscle relaxation
Downstream effect
Antidepressant-like activity in forced swim test and tail suspension test; reduced A1-like reactive astrocyte activation; neuroprotection via NF-κB pathway modulationDjillani 2017Cong 2023Wu 2021
Transient reduction in neuromuscular signal transmission, decreased muscle contraction amplitude, wrinkle depth reduction
Feedback intact?
N/A — direct ion channel blockade; not receptor-mediated endocrine axis
N/A — topical cosmetic, no systemic endocrine axis
Origin
Synthetic truncation of spadin (PE 12-28), itself derived from the sortilin propeptide C-terminus. Residues 22-28: Val-Val-Arg-Gly-Trp-Leu-Arg.Djillani 2017Mazella 2018
Synthetic peptide derived from N-terminal fragment of SNAP-25 protein (synaptosomal-associated protein 25 kDa)
Antibody development
Not reported in animal studies
—
02Dosage Protocols
Parameter
PE 22-28
SNAP-8
Animal dose (antidepressant)
0.3–3 µg/kg IP
Effective in forced swim test, tail suspension test, CUMS models.
—
Animal dose (neuroprotection)
0.03 µg/kg IPPietri 2019
Low-dose TREK-1 activation post-stroke for 7 days, then high-dose blockade.
—
Frequency
Once daily
Sustained antidepressant effect over 7+ days.
—
Onset (animal)
Within hours (acute); full effect 4–7 days
—
Comparison to fluoxetine
PE 22-28 outperforms fluoxetine in CUMS-sensitive rats by day 7
Chronic administration shows superior long-term efficacy.
—
Human equivalent (extrapolated)
Not established — no clinical trials
Allometric scaling from rodent data unavailable.
—
Evidence basis
Multiple rodent RCTs; behavioral + electrophysiology endpointsDjillani 2017Qi 2018Wu 2021
RCT, in vitro skin penetration studies
Typical concentration
—
2–10% in cosmetic formulationsLupin 2024Raikou 2017
Commercial products typically use 5–10%.
Treatment duration
—
20–60 days for visible effectRaikou 2017
Skin microtopography improvements measured at 20-day intervals.
Formulation type
—
Oil-in-water emulsion, serum, cream
Application site
—
Facial skin — glabellar lines, crow's feet, forehead
03Metabolic / Fat Loss Evidence
04Side Effects & Safety
Parameter
PE 22-28
SNAP-8
Toxicity (animal)
No adverse effects reported at therapeutic doses
—
Cardiovascular (theoretical)
TREK-1 expressed in cardiac tissue; arrhythmia risk unclear
—
Weight change
Not reported in animal studies
—
Neurological
No seizures or behavioral abnormalities noted
—
Long-term safety
Unknown — longest animal study 28 days
—
Cytotoxicity
—
Concentration-dependent antiproliferative effect observed in vitro; IC50 ~10 mg/mL (argireline, 6-AA analogue)
Commercial formulations typically use 0.05–0.1 mg/mL, well below cytotoxic threshold.
Skin irritation
—
Minimal; well-tolerated in clinical use
Peptide oxidation
—
Methionine residue susceptible to oxidation in formulation; may reduce efficacyKluczyk 2021
Formulation stability issue, not a direct adverse effect.
Hypersensitivity
—
Rare; no widespread allergic reactions reported
Absolute Contraindications
PE 22-28
- ·Human use — no clinical safety data available
SNAP-8
- ·Known hypersensitivity to acetyl octapeptide-3 or formulation excipients
Relative Contraindications
PE 22-28
- ·Cardiac arrhythmia or channelopathy (theoretical TREK-1 cardiac role)
SNAP-8
- ·Active skin infections or open wounds at application site
- ·Neuromuscular disorders (theoretical concern, no documented cases)
05Administration Protocol
Parameter
PE 22-28
SNAP-8
1. Animal protocol (IP)
Dissolved in sterile saline or vehicle. Intraperitoneal injection, 0.3–3 µg/kg body weight. Once daily administration in rodent behavioral studies.
Wash face with gentle cleanser and pat dry. Remove makeup and surface oils to optimize peptide contact.
2. Stability
Shorter peptide length (7 AA) confers improved plasma stability vs 17-AA spadin. Exact storage conditions not detailed in published protocols.Djillani 2017
Apply 1–2 drops or pea-sized amount of SNAP-8 serum or cream to target areas (forehead, glabellar lines, crow's feet). Gently massage until absorbed.
3. BBB penetration
Enhanced CNS bioavailability vs full spadin, likely due to smaller size. Mechanism (passive diffusion vs active transport) not fully characterized.
Twice daily — morning and evening. Allow 2–3 minutes for absorption before applying additional skincare products.
4. Human formulation
Not established — peptide synthesis methods for research use only. No pharmaceutical-grade formulation available.
Apply before heavier creams or occlusive moisturizers. Peptides penetrate best from water-based serums on clean skin.
5. Storage
—
Store at room temperature, away from direct sunlight. Refrigeration may extend shelf life of formulations containing unstable peptides.
6. Duration
—
Consistent use for 20–60 days required for visible wrinkle reduction. Effects are temporary and reverse upon discontinuation.