Comparison
Metformin vs Testosterone
Side-by-side of Metformin and Testosterone. Every row below is pulled from the compound schema and will update as our data grows. For deeper reads, follow through to each compound page.
Metformin
Metformin for longevity: biguanide mechanism of action, TAME trial status, anti-aging dosage, weight loss data, life extension evidence in non-diabetics.
Testosterone
Testosterone replacement therapy for hypogonadism: TRAVERSE 2023 cardiovascular data, cypionate dosing, body composition gains, Schedule III status.
Effects at a glance
Metformin
- •Reduces HbA1c by ~1.0 to 1.5 percentage points in type 2 diabetes; first-line agent in major guidelines
- •DPP trial: 31% reduction in T2DM incidence in adults with prediabetes over 2.8 years
- •Suppresses hepatic gluconeogenesis via AMPK activation and complex I inhibition
- •Long-term use depletes B12; annual monitoring recommended after year 2
- •Lifespan extension in non-diabetic humans is not established; TAME trial pending
- •MASTERS trial reported blunted resistance-training hypertrophy in older adults
Testosterone
- •Primary androgen; FDA approved for hypogonadism with confirmed deficiency and symptoms
- •Testosterone Trials (2016) showed sexual function and bone density improvements in older hypogonadal men
- •TRAVERSE 2023 (n=5,246) found non-inferiority on MACE versus placebo, with higher AF and PE rates
- •Schedule III controlled substance in US; WADA banned in sport
- •Aromatizes to estradiol; converts to DHT via 5-alpha reductase; both metabolites matter clinically
- •Erythrocytosis (HCT above 54%) affects 5 to 25% of users and is the most common dose-limiting effect
Side-by-side
| Attribute | Metformin | Testosterone |
|---|---|---|
| Category | pharmaceutical | hormone |
| Also known as | Glucophage, Fortamet, Glumetza, dimethylbiguanide | TRT, testosterone replacement therapy, testosterone cypionate, testosterone enanthate, Androgel, Testim |
| Half-life (hr) ↗ | 6 | 192 |
| Typical dose (mg) ↗ | 1500 | 150 |
| Dosing frequency | 1 to 3 times daily with meals; XR once daily | weekly to twice-weekly (cypionate/enanthate IM or SC); daily (topical, oral); every 3 to 6 months (pellet) |
| Routes | oral | intramuscular, subcutaneous, topical, buccal, subcutaneous (pellet), oral |
| Onset (hr) | 1 | 24 |
| Peak (hr) | 2.5 | 72 |
| Molecular weight | 129.16 | 288.42 |
| Molecular formula | C4H11N5 | C19H28O2 |
| Mechanism | Suppresses hepatic gluconeogenesis primarily via AMPK activation and complex I inhibition; modestly improves peripheral insulin sensitivity and shifts gut microbiome composition. | Androgen receptor agonist driving anabolic gene transcription in muscle, bone, brain, and androgen-sensitive tissue. Aromatized to estradiol and 5-alpha-reduced to DHT, both with distinct downstream effects. |
| Legal status | Prescription only (FDA approved for type 2 diabetes 1994) | Schedule III controlled substance (US); WADA banned |
| WADA status | allowed | banned |
| DEA / Rx | Rx only (not a controlled substance) | Schedule III |
| Pregnancy | Category B; used in gestational diabetes and PCOS per current guidance | Category X; contraindicated in pregnancy (virilizing effect on female fetus) |
| CAS | 657-24-9 | 58-22-0 |
| PubChem CID | 4091 | 6013 |
| Wikidata | Q19484 | Q150726 |
Safety profile
Metformin
Common side effects
- nausea
- diarrhea
- abdominal discomfort
- metallic taste
- decreased appetite
- B12 depletion (long-term)
Contraindications
- eGFR below 30 mL/min/1.73m2
- acute or chronic metabolic acidosis
- severe hepatic impairment
- acute heart failure
- iodinated contrast within 48 hours
Interactions
- iodinated contrast media: renal injury risk; hold 48 hours peri-imaging(major)
- alcohol (heavy use): elevated lactic acidosis risk(major)
- cimetidine: raises metformin plasma levels via OCT2 inhibition(moderate)
- insulin and sulfonylureas: additive hypoglycemia risk in combination(moderate)
- dolutegravir: raises metformin exposure via OCT2(moderate)
Testosterone
Common side effects
- erythrocytosis
- acne
- oily skin
- fluid retention
- increased body hair
- fertility suppression
- injection-site reactions
Contraindications
- active prostate cancer
- active breast cancer
- untreated severe sleep apnea
- untreated severe BPH
- uncontrolled heart failure
- polycythemia at baseline
Interactions
- warfarin: may potentiate anticoagulant effect; monitor INR(moderate)
- insulin: may improve insulin sensitivity; monitor glucose in diabetics(moderate)
- 5-alpha reductase inhibitors (finasteride): blocks DHT conversion; reduces some androgen effects(moderate)
- aromatase inhibitors (anastrozole): lowers estradiol; risk of over-suppression(moderate)
Which Should You Take?
Testosterone comes out ahead for most readers on the criteria we weight: 3 catalogued goals, controlled substance, oral dosing, with a Tier-A outcome catalogued. Metformin is the right call when one of the conditionals below applies.
- → If your priority is metabolic health and glucose control, pick Metformin.
- → If your priority is healthspan extension, pick Metformin.
- → If your priority is hormonal optimization, pick Testosterone.
- → If your priority is sexual function, pick Testosterone.
Edge case: Testosterone is contraindicated in pregnancy; Metformin is the safer pick if that applies.
Default choice: Testosterone. Wider use case, a Tier-A evidence outcome catalogued, and broader goal coverage. Reach for Metformin only if your priority sits squarely in the goals it owns above.
This verdict is generated from each compound's schema (goals, legal status, evidence outcomes, dosing route). It updates automatically as our compound data evolves; the deeper read sits on each individual compound page.
Common questions
What is the difference between Metformin and Testosterone?
Metformin and Testosterone differ in category (pharmaceutical vs hormone), mechanism, and typical dosing. See the side-by-side table for full details.
Which has a longer half-life, Metformin or Testosterone?
Metformin half-life is 6 hours; Testosterone half-life is 192 hours.
Can you stack Metformin with Testosterone?
Stack compatibility depends on mechanism overlap, legal status, and individual response. Check each compound page for specific interactions and contraindications before combining.
Go deeper