How Oral Minoxidil Works for Hair Loss: Complete Guide
Oral minoxidil is becoming the go-to treatment for hair loss—and for good reason. It's a once-daily pill that works as well as (or better than) topical minoxidil with far better compliance. Here's exactly how it works, proper dosing, timeline for results, and what to expect.
Quick Facts
How it works
Vasodilator (increases blood flow to follicles)
Typical dose for hair loss
2.5mg-5mg once daily (men)
Time to see results
3-6 months
FDA approved for hair loss?
No (off-label use)
The Science: How Minoxidil Grows Hair
Minoxidil was originally developed as a blood pressure medication. Doctors noticed patients were growing more hair—and the rest is history. Here's what happens when you take it:
Vasodilation (Blood Flow)
Minoxidil is a potassium channel opener that relaxes blood vessel walls. This increases blood flow to hair follicles, delivering more oxygen and nutrients. Better blood supply = healthier follicles.
Extends Anagen (Growth) Phase
Hair grows in cycles: anagen (growth), catagen (transition), and telogen (rest). Minoxidil extends the growth phase, giving hair more time to grow longer and thicker before shedding.
Shortens Telogen (Rest) Phase
By shortening the rest phase, minoxidil gets follicles back into growth mode faster. This is also why you may experience initial shedding—it's pushing resting hairs out to make room for new growth.
Increases Follicle Size
Minoxidil can enlarge miniaturized hair follicles, turning thin "vellus" hairs into thicker "terminal" hairs. This creates the appearance of denser coverage.
Important: Minoxidil Does NOT Block DHT
Unlike finasteride, minoxidil doesn't address the hormonal cause of male pattern baldness (DHT). It stimulates growth but doesn't stop the underlying process causing hair loss. This is why many doctors recommend combining minoxidil with finasteride for comprehensive treatment.
Oral vs Topical: Why Oral Works Differently
When you apply minoxidil topically, it has to be converted to its active form (minoxidil sulfate) by an enzyme in your scalp called sulfotransferase. Here's the catch:
- •Some people have low sulfotransferase: This is why topical doesn't work for everyone (~40% of non-responders)
- •Oral bypasses this: When you take minoxidil orally, it's converted in your liver—not dependent on scalp enzymes
- •More consistent delivery: Oral provides steady systemic levels vs. variable topical absorption
This is why oral minoxidil often works for people who didn't respond to topical treatment.
Dosing Guide
| Population | Starting Dose | Typical Dose | Maximum |
|---|---|---|---|
| Men | 1.25-2.5mg/day | 2.5-5mg/day | 5mg/day |
| Women | 0.625-1.25mg/day | 1.25-2.5mg/day | 2.5mg/day |
Doses higher than 5mg/day significantly increase cardiovascular side effects. For hair loss, higher is NOT better.
Research shows the "sweet spot" for men is 2.5mg to 5mg daily:
- •2.5mg: Effective for most, fewer side effects, what Roman offers
- •5mg: May be slightly more effective, more body hair growth, what Hims offers (as 3mg chewable)
- •1mg: Studies show similar results to topical, good for those worried about side effects
What to Expect: Timeline
Weeks 1-4: Initial Shedding (Normal!)
Many people experience increased hair fall in the first few weeks. This is actually a good sign—minoxidil is pushing resting hairs out to make room for new growth. Don't panic and quit.
Weeks 4-8: Body Hair May Appear
If you're going to experience hypertrichosis (increased body hair), it usually starts around this time. Face, arms, and back are common areas.
Month 3: Early Results Visible
Most people start seeing improvement around the 3-month mark. Hair may look thicker, and shedding should have normalized. Take photos monthly to track progress.
Month 6: Full Effect
By 6 months, you should see the full benefit. In studies, 100% of participants showed some improvement in hair density by this point, with 43% showing "excellent" improvement.
Month 12+: Maintenance
Results continue to improve through the first year. After that, you're maintaining gains. If you stop taking minoxidil, expect to lose the new hair over 3-6 months.
How to Take It
- ✓Take once daily (morning or evening—doesn't matter)
- ✓With or without food
- ✓Same time each day for consistency
- ✓Don't double up if you miss a dose—just take the next one as scheduled
- ✓Give it at least 6 months before judging effectiveness
Who Should NOT Take Oral Minoxidil
Do not take oral minoxidil if you have:
- • Heart disease or heart failure
- • History of heart attack
- • Pheochromocytoma (adrenal tumor)
- • Uncontrolled high blood pressure
- • Are pregnant or planning pregnancy
Use with caution: If you take blood pressure medications, your doctor may need to adjust doses.
Combining with Other Treatments
Oral minoxidil is often combined with other hair loss treatments:
Minoxidil + Finasteride
The gold standard combination. Finasteride blocks DHT (the cause), minoxidil stimulates growth. Studies show this combo is more effective than either alone.
Minoxidil + Topical Minoxidil
Not typically recommended—you get the side effects of both with minimal additional benefit. Choose one or the other.
Key Takeaways
- 1. Minoxidil is a vasodilator that increases blood flow and extends the hair growth phase
- 2. It does NOT block DHT—consider combining with finasteride for comprehensive treatment
- 3. Oral bypasses the scalp enzyme issue that makes topical ineffective for some people
- 4. Typical dose is 2.5-5mg daily for men
- 5. Expect results around 3-6 months—don't quit early
- 6. Initial shedding is normal and actually a good sign
- 7. Results are maintenance—stop taking it and you'll lose the gains
Medical Disclaimer: This article is for informational purposes only. Oral minoxidil requires a prescription and is used off-label for hair loss. Consult a healthcare provider before starting any new medication.