Comparison
Ashwagandha vs Metformin
Side-by-side of Ashwagandha and Metformin. 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.
Ashwagandha
Ashwagandha supplement guide: KSM-66 and Sensoril extracts at 300-600 mg/day cut morning cortisol and stress in RCTs. Dose, side effects, testosterone data.
Metformin
Metformin for longevity: biguanide mechanism of action, TAME trial status, anti-aging dosage, weight loss data, life extension evidence in non-diabetics.
Effects at a glance
Ashwagandha
- •Reduces morning serum cortisol by ~20 to 30% at 300 to 600 mg/day standardized extract over 8 weeks
- •Lowers subjective stress on DASS-21 and PSS scales versus placebo in chronically stressed adults
- •Modest grip-strength and 1-RM gains of ~5 to 8% in trained men when paired with resistance training
- •Improves self-reported sleep quality and onset latency in adults with insomnia symptoms
- •Small testosterone increases (~10 to 15%) reported in stressed or subfertile men, less clear in healthy populations
- •May raise free T3 and T4; can interact with levothyroxine and unmask subclinical hyperthyroidism
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
Side-by-side
| Attribute | Ashwagandha | Metformin |
|---|---|---|
| Category | natural | pharmaceutical |
| Also known as | Withania somnifera, KSM-66, Sensoril | Glucophage, Fortamet, Glumetza, dimethylbiguanide |
| Half-life (hr) ↗ | 10 | 6 |
| Typical dose (mg) ↗ | 600 | 1500 |
| Dosing frequency | daily | 1 to 3 times daily with meals; XR once daily |
| Routes | oral | oral |
| Onset (hr) | 2 | 1 |
| Peak (hr) | - | 2.5 |
| Molecular weight | - | 129.16 |
| Molecular formula | - | C4H11N5 |
| Mechanism | GABAergic modulation and HPA-axis attenuation; withanolides reduce cortisol secretion and inhibit NF-kB signaling. | Suppresses hepatic gluconeogenesis primarily via AMPK activation and complex I inhibition; modestly improves peripheral insulin sensitivity and shifts gut microbiome composition. |
| Legal status | Dietary supplement in most jurisdictions; regulated in Denmark | Prescription only (FDA approved for type 2 diabetes 1994) |
| WADA status | allowed | allowed |
| DEA / Rx | OTC supplement | Rx only (not a controlled substance) |
| Pregnancy | Not recommended | Category B; used in gestational diabetes and PCOS per current guidance |
| CAS | - | 657-24-9 |
| PubChem CID | - | 4091 |
| Wikidata | Q310109 | Q19484 |
Safety profile
Ashwagandha
Common side effects
- mild GI upset
- drowsiness
- headache
Contraindications
- pregnancy
- autoimmune disease (theoretical immune stimulation)
- hyperthyroidism
- concurrent sedative use
Interactions
- benzodiazepines: additive CNS depression(moderate)
- thyroid hormone (levothyroxine): may raise T3/T4, altering dose requirements(moderate)
- immunosuppressants: theoretical antagonism via immune stimulation(moderate)
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)
Which Should You Take?
Ashwagandha comes out ahead for most readers on the criteria we weight: 3 catalogued goals, OTC dietary supplement, oral dosing, with a Tier-B outcome catalogued. Metformin is the right call when one of the conditionals below applies.
- → If your priority is stress and HPA-axis regulation, pick Ashwagandha.
- → If your priority is focus or working memory, pick Ashwagandha.
- → If your priority is metabolic health and glucose control, pick Metformin.
- → If your priority is healthspan extension, pick Metformin.
Edge case: If you want to avoid prescription-only, Ashwagandha is the more accessible choice.
Default choice: Ashwagandha. Lower friction to source, 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 Ashwagandha and Metformin?
Ashwagandha and Metformin differ in category (natural vs pharmaceutical), mechanism, and typical dosing. See the side-by-side table for full details.
Which has a longer half-life, Ashwagandha or Metformin?
Ashwagandha half-life is 10 hours; Metformin half-life is 6 hours.
Can you stack Ashwagandha with Metformin?
Stack compatibility depends on mechanism overlap, legal status, and individual response. Check each compound page for specific interactions and contraindications before combining.
Go deeper