Comparison
Alpha-Lipoic Acid vs Melatonin
Side-by-side of Alpha-Lipoic Acid and Melatonin. 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.
Melatonin
Melatonin as a sleep supplement: 0.3-1 mg matches physiological output, 3-10 mg is pharmacological. Shifts circadian phase, shortens sleep latency.
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
Melatonin
- •Shortens sleep onset latency by ~7 to 12 minutes at physiological 0.3 to 1 mg doses
- •Advances circadian phase when taken 30 to 60 minutes before target bedtime, useful for jet lag and shift work
- •Does not meaningfully increase total sleep time in healthy adults without circadian misalignment
- •Endogenous nighttime production is not suppressed by short-term exogenous supplementation
- •Higher doses (3 to 10 mg) raise plasma levels above physiological range and often increase morning grogginess
- •Effective for delayed sleep-wake phase disorder and reducing jet-lag severity in eastward travel
Side-by-side
| Attribute | Alpha-Lipoic Acid | Melatonin |
|---|---|---|
| Category | supplement | supplement |
| Also known as | ALA, thioctic acid, R-ALA, R-lipoic acid | N-acetyl-5-methoxytryptamine |
| Half-life (hr) ↗ | 0.5 | 0.75 |
| Typical dose (mg) ↗ | 600 | 0.5 |
| Dosing frequency | 1 to 3 times daily on empty stomach | daily, 30 to 60 minutes before target sleep time |
| Routes | oral, iv | oral, sublingual |
| Onset (hr) | 0.5 | 0.5 |
| Peak (hr) | 1 | 1 |
| Molecular weight | 206.33 | 232.28 |
| Molecular formula | C8H14O2S2 | C13H16N2O2 |
| 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. | Agonist at MT1 and MT2 receptors in the suprachiasmatic nucleus, signaling biological night and promoting sleep-onset gating plus circadian phase shifts. |
| Legal status | Dietary supplement (US, UK, Canada, most EU); prescription drug for diabetic neuropathy in Germany | OTC in US; prescription in UK, EU, Japan |
| WADA status | allowed | allowed |
| DEA / Rx | Not scheduled | OTC supplement in US; Rx in UK, EU, Japan, Australia |
| Pregnancy | Insufficient data; precautionary avoidance | Insufficient data; not routinely recommended |
| CAS | 62-46-4 | 73-31-4 |
| PubChem CID | 864 | 896 |
| Wikidata | Q161227 | Q179243 |
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)
Melatonin
Common side effects
- vivid dreams
- morning grogginess (higher doses)
- headache
- dizziness
Contraindications
- autoimmune disease (theoretical)
- concurrent anticoagulant therapy without monitoring
Interactions
- fluvoxamine: CYP1A2 inhibition raises melatonin levels substantially(major)
- warfarin: possible increased bleeding risk(moderate)
- benzodiazepines and alcohol: additive sedation(moderate)
- antihypertensives: may alter blood pressure response(minor)
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. Melatonin is the right call when one of the conditionals below applies.
- → If your priority is metabolic health and glucose control, pick Alpha-Lipoic Acid.
- → If your priority is healthspan extension, pick Alpha-Lipoic Acid.
- → If your priority is sleep onset or sleep quality, pick Melatonin.
- → If your priority is circadian regulation, pick Melatonin.
Default choice: Alpha-Lipoic Acid. Lower friction to source, and broader goal coverage. Reach for Melatonin 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 Melatonin?
Alpha-Lipoic Acid and Melatonin differ in category (supplement vs supplement), mechanism, and typical dosing. See the side-by-side table for full details.
Which has a longer half-life, Alpha-Lipoic Acid or Melatonin?
Alpha-Lipoic Acid half-life is 0.5 hours; Melatonin half-life is 0.75 hours.
Can you stack Alpha-Lipoic Acid with Melatonin?
Stack compatibility depends on mechanism overlap, legal status, and individual response. Check each compound page for specific interactions and contraindications before combining.
Go deeper