Comparison
Alpha-Lipoic Acid vs Metformin
Side-by-side of Alpha-Lipoic Acid 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.
Alpha-Lipoic Acid
Alpha lipoic acid supplement guide: 600 mg/day oral dosing, R-ALA vs racemic absorption, neuropathy trial data, antioxidant mechanism, interactions.
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
Alpha-Lipoic Acid
- •Approved Rx for diabetic neuropathy in Germany at 600 mg/day IV (Thioctacid) since 1960s
- •Improves neuropathy symptoms (TSS, NIS) at 600 mg/day IV across ALADIN and SYDNEY trials
- •R-ALA enantiomer absorbs 40-100% better than racemic mixtures
- •Activates AMPK; produces small HbA1c reductions in T2DM
- •Plasma half-life ~30 minutes; split dosing or sustained-release is standard
- •Hypoglycemia risk with insulin or sulfonylureas; medication adjustment may be required
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 | Alpha-Lipoic Acid | Metformin |
|---|---|---|
| Category | supplement | pharmaceutical |
| Also known as | ALA, thioctic acid, R-ALA, R-lipoic acid | Glucophage, Fortamet, Glumetza, dimethylbiguanide |
| Half-life (hr) ↗ | 0.5 | 6 |
| Typical dose (mg) ↗ | 600 | 1500 |
| Dosing frequency | 1 to 3 times daily on empty stomach | 1 to 3 times daily with meals; XR once daily |
| Routes | oral, iv | oral |
| Onset (hr) | 0.5 | 1 |
| Peak (hr) | 1 | 2.5 |
| Molecular weight | 206.33 | 129.16 |
| Molecular formula | C8H14O2S2 | C4H11N5 |
| Mechanism | Dual lipid- and water-soluble antioxidant; redox cycles with dihydrolipoic acid (DHLA) to scavenge ROS, regenerate vitamin E and C, and chelate transition metals. Activates AMPK in liver and muscle; cofactor for pyruvate and alpha-ketoglutarate dehydrogenase complexes. | 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 (US, UK, Canada, most EU); prescription drug for diabetic neuropathy in Germany | Prescription only (FDA approved for type 2 diabetes 1994) |
| WADA status | allowed | allowed |
| DEA / Rx | Not scheduled | Rx only (not a controlled substance) |
| Pregnancy | Insufficient data; precautionary avoidance | Category B; used in gestational diabetes and PCOS per current guidance |
| CAS | 62-46-4 | 657-24-9 |
| PubChem CID | 864 | 4091 |
| Wikidata | Q161227 | Q19484 |
Safety profile
Alpha-Lipoic Acid
Common side effects
- nausea
- abdominal discomfort
- diarrhea
- sulfurous odor
- rash (rare)
Contraindications
- pregnancy and lactation (insufficient safety data)
- active insulin autoimmune syndrome predisposition
Interactions
- insulin and sulfonylureas: additive hypoglycemia; medication dose adjustment may be required(major)
- thyroid hormone: may reduce T4 to T3 conversion at high doses(moderate)
- biotin: ALA competes with biotin uptake; chronic use can induce biotin insufficiency(minor)
- iron supplements: ALA chelates iron and reduces absorption; separate dosing(moderate)
- chemotherapy (oxidative-stress-dependent agents): theoretical interference; coordinate with oncology team(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?
Alpha-Lipoic Acid 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 long-term neuroprotection, pick Alpha-Lipoic Acid.
- → If your priority is metabolic health and glucose control, pick Alpha-Lipoic Acid.
- → If your priority is healthspan extension, pick Alpha-Lipoic Acid.
Edge case: If you want to avoid prescription-only, Alpha-Lipoic Acid is the more accessible choice.
Default choice: Alpha-Lipoic Acid. 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 Alpha-Lipoic Acid and Metformin?
Alpha-Lipoic Acid and Metformin differ in category (supplement vs pharmaceutical), mechanism, and typical dosing. See the side-by-side table for full details.
Which has a longer half-life, Alpha-Lipoic Acid or Metformin?
Alpha-Lipoic Acid half-life is 0.5 hours; Metformin half-life is 6 hours.
Can you stack Alpha-Lipoic Acid 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