Side-by-side · Research reference

SS-31vsThymosin α-1

Side-by-side comparison across mechanism, dosage, evidence, side effects, administration, and stack synergies. Citations on every claim where available.

APhase 3Reviewed9/43 cited

BPhase 3Reviewed8/39 cited

SS-31

Cardiolipin-binding · Mitochondrial protective

40 mgDaily doseSzeto 2014

Phase 3Evidence levelSzilagyi 2009 Szeto 2014

~3 hrHalf-life

SQ · Abdomen · Once daily

Thymosin α-1

Immune modulator · Approved (some countries)

1.6 mgPer doseIyer 2007

Phase 3Evidence levelIyer 2007 Camerini 2001

~2 hrHalf-life

SQ · 2× weekly · 6+ months for chronic indications

01Mechanism of Action

Parameter

SS-31

Thymosin α-1

Primary target

Cardiolipin in inner mitochondrial membraneSzeto 2014

Toll-like receptor 9 (TLR9) + T-cell maturation pathwayCamerini 2001

Pathway

Cardiolipin binding → cristae stabilisation → ETC integrity → reduced ROS + preserved ATP synthesisSzeto 2014 Szilagyi 2009

TLR9 activation → ↑ IFN-α + IL-2 + IFN-γ → enhanced T-cell function + dendritic cell maturationIyer 2007

Downstream effect

Mitochondrial bioenergetic preservation; cardio-, neuro-, and reno-protective effects in animal + clinical studiesSzeto 2014

Restored T-cell function, improved viral clearance, anti-tumour adjuvant effectsIyer 2007

Feedback intact?

—

Origin

Synthetic tetrapeptide D-Arg-Dmt-Lys-Phe-NH₂; cell-permeable, mitochondrial-selectiveSzeto 2014

Synthetic 28-AA peptide identical to natural Tα-1 isolated from thymus extractCamerini 2001

Antibody development

—

02Dosage Protocols

Parameter

SS-31

Thymosin α-1

Standard dose

40 mg / day SQ (clinical trials)Szeto 2014

Anecdotal community range 5-10 mg/day. Phase 3 trials use 40 mg.

—

Frequency

Once daily

2× weekly (Mon/Thu typical)

Lower / starter dose

5 mg / day (anecdotal)

0.8 mg per injection

Evidence basis

Multiple Phase 3 trials (Barth, AMD, ischemia-reperfusion)Szeto 2014 Szilagyi 2009

Phase 3 + approved (35+ countries as Zadaxin)Iyer 2007

Duration

Indefinite for mitochondrial disease; cycled for healthspan use

6–12 months for chronic indications

Reconstitution

Bacteriostatic water

Sterile water for injection per vial label

Timing

Morning fasted preferred; pre-workout for exercise-induced mitochondrial stress

No specific time

Half-life

~3 h plasma; tissue uptake longer

~2 hours plasma; tissue effect days

Standard dose (HBV/HCV)

—

1.6 mg SQ 2× weekly × 6–12 monthsIyer 2007

04Side Effects & Safety

Parameter

SS-31

Thymosin α-1

Injection site reaction

Erythema, mild pruritus

Erythema, mild discomfort

GI symptoms

Nausea (uncommon)

Rare nausea

Headache

Reported in some Phase 3 trials

—

Cardiovascular

Cardio-protective in studies; no signal of harm

—

Long-term safety

Phase 3 data over 24+ months; no major safety signalsSzeto 2014

—

Pregnancy / OB

Avoid — insufficient data

Avoid

Fatigue

—

Common during initial weeks

Fever / flu-like

—

Mild interferon-like response possible

Autoimmune

—

Theoretical risk; caution in active autoimmune disease

Cancer risk

—

No signal — used as adjuvant in oncology

Absolute Contraindications

SS-31

·Pregnancy / breastfeeding
·Hypersensitivity to peptide

Thymosin α-1

·Pregnancy / breastfeeding
·Hypersensitivity to peptide
·Concurrent immunosuppressant therapy (transplant patients)

Relative Contraindications

SS-31

·None established

Thymosin α-1

·Active autoimmune disease
·Severe immunocompromised state without supervision

05Administration Protocol

Parameter

SS-31

Thymosin α-1

1. Reconstitution

Add bacteriostatic water per label. Light-protected handling.

Add 1 mL sterile water per 1.6 mg vial → 1.6 mg/mL.

2. Injection site

SQ — abdomen or thigh. Rotate sites.

SQ — abdomen, thigh, or upper arm. Rotate sites.

3. Timing

Morning fasted; pre-workout for exercise-augmented mitochondrial stress.

2× weekly, e.g. Monday + Thursday.

4. Storage

Lyophilised: refrigerate, light-protected. Reconstituted: refrigerate ≤30 days.

Lyophilised: refrigerate. Reconstituted: refrigerate, use within 24 h.

5. Needle

29–31G, 4–8 mm insulin syringe.

27–31G, 4–8 mm insulin syringe.

06Stack Synergy

SS-31

+ MOTS-c

Moderate

View MOTS-c →

SS-31 and MOTS-c address mitochondrial decline through complementary axes. SS-31 protects existing mitochondrial structure (cardiolipin binding, cristae stabilisation). MOTS-c upregulates AMPK/PGC-1α, triggering biogenesis of new mitochondria. Together they pair preservation with renewal — anecdotally favoured in healthspan and post-cardio-event recovery protocols.

SS-31: 5–10 mg SQ · daily morning
MOTS-c: 5 mg SQ · 2× per week pre-workout
Primary benefit: Mitochondrial preservation + biogenesis

Thymosin α-1

— no documented stacks