Comparison
Armodafinil vs Low-Dose Naltrexone
Side-by-side of Armodafinil and Low-Dose Naltrexone. 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.
Low-Dose Naltrexone
Low dose naltrexone at 1.5 to 4.5 mg, one-tenth the 50 mg addiction dose. Compounded Rx. Small trials in fibromyalgia, Crohn's, Hashimoto's.
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
Low-Dose Naltrexone
- •Off-label use at 1.5 to 4.5 mg, roughly one-tenth the FDA-approved 50 mg addiction-treatment dose
- •Proposed mechanisms include brief opioid receptor blockade triggering rebound endogenous opioid release, plus TLR4 antagonism
- •Compounded prescription only; insurance rarely covers; cash prices 20 to 80 USD per month
- •Younger 2013 reported ~30% pain reduction in fibromyalgia at 4.5 mg in a small crossover trial
- •Smith 2011 reported endoscopic improvement in active Crohn's disease (n=40 placebo-controlled)
- •Vivid dreams affect 20 to 40% in first 2 weeks; manageable by switching to morning dosing
Side-by-side
| Attribute | Armodafinil | Low-Dose Naltrexone |
|---|---|---|
| Category | pharmaceutical | pharmaceutical |
| Also known as | Nuvigil, R-modafinil, (R)-(-)-modafinil | LDN, naltrexone (low dose) |
| Half-life (hr) ↗ | 15 | 4 |
| Typical dose (mg) ↗ | 150 | 4.5 |
| Dosing frequency | daily, morning | once daily, typically at bedtime |
| Routes | oral | oral |
| Onset (hr) | 1 | 1 |
| Peak (hr) | 3 | 1.5 |
| Molecular weight | 273.35 | 341.4 |
| Molecular formula | C15H15NO2S | C20H23NO4 |
| Mechanism | Weak dopamine reuptake inhibition plus downstream activation of histaminergic, noradrenergic, and orexinergic wake systems; R-enantiomer of modafinil with longer half-life. | Brief mu-opioid receptor antagonism proposed to trigger compensatory upregulation of endogenous opioids; secondary TLR4 antagonism on microglia and immune cells contributes to anti-inflammatory effect. |
| Legal status | Schedule IV (US); prescription-only globally; not a supplement | Off-label compounded prescription (naltrexone is FDA approved for opioid and alcohol use disorder at 50 mg) |
| WADA status | banned | allowed |
| DEA / Rx | Schedule IV | Rx only (not a controlled substance) |
| Pregnancy | Not recommended | Insufficient data; not routinely recommended |
| CAS | 112111-43-0 | 16590-41-3 |
| PubChem CID | 9148206 | 5360515 |
| Wikidata | Q4791953 | Q426444 |
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)
Low-Dose Naltrexone
Common side effects
- vivid dreams
- sleep disruption
- headache
- mild GI upset
- fatigue (early)
Contraindications
- concurrent opioid use
- acute hepatitis or liver failure
- opioid dependence
- pregnancy (insufficient data)
Interactions
- opioid analgesics (oxycodone, morphine, codeine): blocks analgesic effect; precipitates withdrawal in dependent users(major)
- tramadol: blocks opioid component of analgesia(major)
- thyroid hormone replacement: may alter dose requirements after immune modulation; monitor TSH(minor)
Which Should You Take?
Armodafinil comes out ahead for most readers on the criteria we weight: 3 catalogued goals, controlled substance, oral dosing, with a Tier-A outcome catalogued. Low-Dose Naltrexone 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 immune support, pick Low-Dose Naltrexone.
- → If your priority is pain modulation, pick Low-Dose Naltrexone.
Edge case: Half-lives differ materially (Armodafinil ~15 hr vs Low-Dose Naltrexone ~4 hr). Armodafinil reaches steady state faster; Low-Dose Naltrexone is easier to dial in if tolerability is uncertain.
Default choice: Armodafinil. Wider use case, a Tier-A evidence outcome catalogued, and broader goal coverage. Reach for Low-Dose Naltrexone 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 Low-Dose Naltrexone?
Armodafinil and Low-Dose Naltrexone differ in category (pharmaceutical vs pharmaceutical), mechanism, and typical dosing. See the side-by-side table for full details.
Which has a longer half-life, Armodafinil or Low-Dose Naltrexone?
Armodafinil half-life is 15 hours; Low-Dose Naltrexone half-life is 4 hours.
Can you stack Armodafinil with Low-Dose Naltrexone?
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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