Side-by-side · Research reference
PE 22-28vsThymalin
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-MechanisticAUTO-DRAFTED12/40 cited
PE 22-28
TREK-1 Antagonist · Pre-Clinical
IP · SQ · Once Daily (animal models)Djillani 2017Pietri 2019
Thymalin
Immune restorer · Russian peptide bioregulator
IM · Daily for 5–10 days · 1-2×/year
01Mechanism of Action
Parameter
PE 22-28
Thymalin
Primary target
TREK-1 two-pore-domain potassium channelDjillani 2017Ma 2020
T-cell precursors + thymus-axis maturation pathwayKhavinson 2002
Pathway
TREK-1 channel blockade → Neuronal membrane depolarisation → Enhanced hippocampal excitability → Increased neuroplasticity
Modulation of T-cell differentiation + thymic hormone restoration in age-involuted thymusKhavinson 2002
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
Restored T-cell populations, improved immune surveillance, reduced infection rates in elderlyKhavinson 2002
Feedback intact?
N/A — direct ion channel blockade; not receptor-mediated 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
Polypeptide fraction isolated from calf thymus extractKhavinson 2002
Antibody development
Not reported in animal studies
—
02Dosage Protocols
Parameter
PE 22-28
Thymalin
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.
Once daily during cycle
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
Russian clinical + in vitroKhavinson 2002
Lower / starter dose
—
2.5 mg / day
Duration
—
5–10 day cycles, 1–2× per year
Reconstitution
—
Saline or bacteriostatic water
Timing
—
Morning preferred
Half-life
—
Hours (estimated)
04Side Effects & Safety
Parameter
PE 22-28
Thymalin
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
Limited Western data
Injection site reaction
—
Mild erythema at IM site
Allergic reaction
—
Rare hypersensitivity to bovine-derived polypeptide
Autoimmune flare
—
Theoretical risk in active autoimmune disease
Pregnancy / OB
—
Avoid
Absolute Contraindications
PE 22-28
- ·Human use — no clinical safety data available
Thymalin
- ·Pregnancy / breastfeeding
- ·Bovine protein hypersensitivity
Relative Contraindications
PE 22-28
- ·Cardiac arrhythmia or channelopathy (theoretical TREK-1 cardiac role)
Thymalin
- ·Active autoimmune disease
- ·Concurrent immunosuppressant therapy
05Administration Protocol
Parameter
PE 22-28
Thymalin
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.
Add 1–2 mL saline or bacteriostatic water per 10 mg vial.
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
Intramuscular — deltoid or gluteal. Rotate sites.
3. BBB penetration
Enhanced CNS bioavailability vs full spadin, likely due to smaller size. Mechanism (passive diffusion vs active transport) not fully characterized.
Morning preferred during cycle.
4. Human formulation
Not established — peptide synthesis methods for research use only. No pharmaceutical-grade formulation available.
Lyophilised: refrigerate, light-protected. Reconstituted: use immediately.
5. Needle
—
23–25G, 25–38 mm IM needle.
06Stack Synergy
PE 22-28
— no documented stacks
Thymalin
+ Thymosin α-1
ModerateThymalin is a polypeptide complex; Thymosin α-1 is a single purified peptide. Both target the thymus-axis but at different levels — Thymalin restores broad thymic signaling; Tα-1 provides a specific molecular activator. Anecdotally combined for elderly immune support.
- Thymalin
- 5–10 mg IM · daily × 7 days
- Thymosin α-1
- 1.6 mg SQ · 2× weekly during the cycle
- Primary benefit
- Broad thymic restoration + targeted immune activation