Comparison
Alpha-Lipoic Acid vs Modafinil
Side-by-side of Alpha-Lipoic Acid and Modafinil. 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.
Modafinil
Modafinil cognitive enhancement profile: wakefulness-promoting agent, 100-200 mg dosing, 12-15 hour half-life, off-label nootropic use, Schedule IV status.
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
Modafinil
- •FDA approved in 1998 for narcolepsy, with later additions for shift-work sleep disorder and OSA residual sleepiness
- •Schedule IV controlled substance in the US; prescription-only in EU, UK, Australia
- •Increases wakefulness via weak dopamine reuptake inhibition plus histaminergic, noradrenergic, and orexinergic activation
- •Long half-life of 12 to 15 hours requires morning dosing to avoid sleep disruption
- •Modest cognitive enhancement signal in non-sleep-deprived adults at 100 to 200 mg (Battleday meta-review 2015)
- •Substantial CYP3A4 induction reduces hormonal contraceptive efficacy; barrier methods recommended
Side-by-side
| Attribute | Alpha-Lipoic Acid | Modafinil |
|---|---|---|
| Category | supplement | pharmaceutical |
| Also known as | ALA, thioctic acid, R-ALA, R-lipoic acid | Provigil, Modalert, Modvigil, diphenylmethylsulfinyl-acetamide |
| Half-life (hr) ↗ | 0.5 | 13 |
| Typical dose (mg) ↗ | 600 | 200 |
| Dosing frequency | 1 to 3 times daily on empty stomach | daily, morning |
| Routes | oral, iv | oral |
| Onset (hr) | 0.5 | 1 |
| Peak (hr) | 1 | 3 |
| Molecular weight | 206.33 | 273.35 |
| Molecular formula | C8H14O2S2 | C15H15NO2S |
| 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. | Weak dopamine reuptake inhibition plus downstream activation of histaminergic, noradrenergic, and orexinergic wake-promoting systems. |
| Legal status | Dietary supplement (US, UK, Canada, most EU); prescription drug for diabetic neuropathy in Germany | Schedule IV (US); prescription-only globally; not a supplement |
| WADA status | allowed | banned |
| DEA / Rx | Not scheduled | Schedule IV |
| Pregnancy | Insufficient data; precautionary avoidance | Not recommended |
| CAS | 62-46-4 | 68693-11-8 |
| PubChem CID | 864 | 4236 |
| Wikidata | Q161227 | Q422968 |
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)
Modafinil
Common side effects
- headache
- nausea
- anxiety
- insomnia (with late-day dosing)
- dry mouth
- mild blood pressure elevation
Contraindications
- recent myocardial infarction
- unstable angina
- left ventricular hypertrophy
- significant arrhythmia
- history of Stevens-Johnson syndrome
- psychotic disorders
- pregnancy
- concurrent MAOI use
Interactions
- hormonal contraceptives: CYP3A4 induction reduces contraceptive efficacy; use barrier method(major)
- cyclosporine: reduced cyclosporine levels via CYP3A4 induction(major)
- warfarin: CYP2C9 inhibition raises INR(moderate)
- phenytoin: CYP2C19 inhibition raises phenytoin levels(moderate)
- MAOIs: potential hypertensive reaction(major)
- classical stimulants (amphetamine, methylphenidate): additive cardiovascular and sleep-disruption effects(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. Modafinil 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 wakefulness, pick Modafinil.
- → If your priority is focus or working memory, pick Modafinil.
Edge case: If you want to avoid controlled substance, Alpha-Lipoic Acid is the more accessible choice.
Default choice: Alpha-Lipoic Acid. Lower friction to source, and broader goal coverage. Reach for Modafinil 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 Modafinil?
Alpha-Lipoic Acid and Modafinil 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 Modafinil?
Alpha-Lipoic Acid half-life is 0.5 hours; Modafinil half-life is 13 hours.
Can you stack Alpha-Lipoic Acid with Modafinil?
Stack compatibility depends on mechanism overlap, legal status, and individual response. Check each compound page for specific interactions and contraindications before combining.
Go deeper