Comparison
Armodafinil vs Vitamin D3 + K2
Side-by-side of Armodafinil and Vitamin D3 + K2. 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.
Armodafinil
Armodafinil is the R-enantiomer sold as Nuvigil. Half-life 10-15 h, 150 mg standard dose, narcolepsy and shift-work approvals, Schedule IV.
Vitamin D3 + K2
Vitamin D3 K2 supplement profile: cholecalciferol at 1000-4000 IU/day corrects deficiency, MK-7 directs calcium to bone, away from arteries.
Effects at a glance
Armodafinil
- •FDA approved in 2007 for narcolepsy, shift-work sleep disorder, and OSA residual sleepiness
- •R-enantiomer of modafinil; 150 mg armodafinil is roughly equivalent to 200 mg modafinil
- •Schedule IV controlled in the US; prescription-only globally
- •Longer terminal half-life of about 15 hours produces extended late-day wakefulness coverage
- •Same CYP3A4 induction as modafinil; reduces hormonal contraceptive efficacy
- •Side-effect profile and dermatologic risk warnings mirror modafinil
Vitamin D3 + K2
- •Reduces non-vertebral fractures 10-20% in older adults at 800 IU/day or above when combined with calcium
- •VITAL trial showed neutral results on primary CV and cancer endpoints at 2000 IU/day over 5 years
- •Vitamin D supplementation reduces respiratory infection incidence ~10-20% in deficient populations
- •K2 MK-7 has 72-hour plasma half-life vs 1-2 hours for MK-4; once-daily dosing is sufficient
- •Synergy hypothesis is largely preclinical; dedicated combination RCTs are limited
- •Daily dosing outperforms bolus dosing for immune and infection outcomes
Side-by-side
| Attribute | Armodafinil | Vitamin D3 + K2 |
|---|---|---|
| Category | pharmaceutical | supplement |
| Also known as | Nuvigil, R-modafinil, (R)-(-)-modafinil | cholecalciferol + menaquinone, D3/K2, vitamin D3 with MK-7 |
| Half-life (hr) ↗ | 15 | 360 |
| Typical dose (mg) ↗ | 150 | 0.05 |
| Dosing frequency | daily, morning | daily with a fat-containing meal |
| Routes | oral | oral |
| Onset (hr) | 1 | 24 |
| Peak (hr) | 3 | 168 |
| Molecular weight | 273.35 | 384.64 |
| Molecular formula | C15H15NO2S | C27H44O (D3); C46H64O2 (MK-7) |
| Mechanism | Weak dopamine reuptake inhibition plus downstream activation of histaminergic, noradrenergic, and orexinergic wake systems; R-enantiomer of modafinil with longer half-life. | D3 converts to calcidiol then calcitriol, activating the vitamin D receptor (VDR) to increase intestinal calcium absorption and modulate immune and bone gene transcription. K2 carboxylates osteocalcin and matrix Gla protein, directing calcium toward bone and inhibiting vascular calcification. |
| Legal status | Schedule IV (US); prescription-only globally; not a supplement | Dietary supplement (global) |
| WADA status | banned | allowed |
| DEA / Rx | Schedule IV | Not scheduled |
| Pregnancy | Not recommended | Recommended at standard doses for fetal bone development; consult clinician at higher doses |
| CAS | 112111-43-0 | 67-97-0 |
| PubChem CID | 9148206 | 5280795 |
| Wikidata | Q4791953 | Q139347 |
Safety profile
Armodafinil
Common side effects
- headache
- nausea
- dizziness
- anxiety
- insomnia (with later-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: additive cardiovascular and sleep-disruption effects(moderate)
Vitamin D3 + K2
Common side effects
- GI upset at high doses
- headache (rare)
- hypercalcemia (only at sustained very high D3 doses)
Contraindications
- hypercalcemia
- sarcoidosis
- active hyperparathyroidism
- warfarin therapy (K2 component requires stable intake)
Interactions
- warfarin: K2 component can affect anticoagulation; maintain stable intake and inform anticoagulation clinic(moderate)
- thiazide diuretics: additive calcium retention; hypercalcemia risk with high-dose D3(moderate)
- digoxin and calcium channel blockers: additive effects from D3-induced hypercalcemia(moderate)
- glucocorticoids: reduced vitamin D efficacy and bone effects(moderate)
- cholestyramine and orlistat: bind fat-soluble vitamins; separate dosing by 2 to 4 hours(moderate)
Which Should You Take?
Vitamin D3 + K2 comes out ahead for most readers on the criteria we weight: 3 catalogued goals, OTC dietary supplement, oral dosing, with a Tier-A outcome catalogued. Armodafinil is the right call when one of the conditionals below applies.
- → If your priority is wakefulness, pick Armodafinil.
- → If your priority is focus or working memory, pick Armodafinil.
- → If your priority is bone density, pick Vitamin D3 + K2.
- → If your priority is healthspan extension, pick Vitamin D3 + K2.
Edge case: If you want to avoid controlled substance, Vitamin D3 + K2 is the more accessible choice.
Default choice: Vitamin D3 + K2. Lower friction to source, a Tier-A evidence outcome catalogued, and broader goal coverage. Reach for Armodafinil 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 Armodafinil and Vitamin D3 + K2?
Armodafinil and Vitamin D3 + K2 differ in category (pharmaceutical vs supplement), mechanism, and typical dosing. See the side-by-side table for full details.
Which has a longer half-life, Armodafinil or Vitamin D3 + K2?
Armodafinil half-life is 15 hours; Vitamin D3 + K2 half-life is 360 hours.
Can you stack Armodafinil with Vitamin D3 + K2?
Stack compatibility depends on mechanism overlap, legal status, and individual response. Check each compound page for specific interactions and contraindications before combining.
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