Does Minoxidil Cause Hair Follicles to Grow? The Science Explained

October 10, 2025 •

4 min read

Androgenetic alopecia, or pattern hair loss, affects an estimated 50 million men and 30 million women in the United States [1.9.3]. A common question is, does minoxidil cause hair follicles to regrow? The answer is nuanced: it revitalizes existing follicles rather than creating new ones [1.3.1, 1.3.2].

Quick Summary

Minoxidil stimulates existing, dormant hair follicles by increasing blood flow and extending the growth phase. It does not create new follicles but can lead to thicker, fuller hair over time by reactivating what is already there.

Key Points

No New Follicles: Minoxidil stimulates and revives existing, dormant hair follicles; it does not create new ones [1.3.1, 1.4.3].
Mechanism of Action: It acts as a vasodilator, increasing blood flow and nutrients to follicles, and as a potassium channel opener, extending the hair's growth phase [1.2.1, 1.2.2].
The 'Dread Shed': An initial, temporary increase in hair shedding is common and indicates the medication is working by pushing old hairs out to make way for new growth [1.7.1, 1.7.3].
Timeline for Results: Initial results may be seen in as little as 8 weeks, with more significant effects appearing around 4-6 months of consistent use [1.2.1, 1.8.3].
Continuous Use Required: Minoxidil is a long-term treatment. If discontinued, any hair that has regrown will likely be lost within 3-6 months [1.10.1].
Minoxidil vs. Finasteride: Minoxidil primarily stimulates growth, while finasteride works by blocking the hormone DHT to prevent follicle shrinkage [1.5.3].
Oral vs. Topical: Oral minoxidil may be more effective for some but carries a higher risk of systemic side effects compared to topical applications [1.6.1, 1.6.3].

The Core Question: Does Minoxidil Create New Hair Follicles?

A common misconception is that minoxidil can generate entirely new hair follicles where they have been lost. The reality is that minoxidil does not create new follicles [1.4.3, 1.3.5]. Instead, its primary function is to revitalize and stimulate existing hair follicles that have become dormant or have shrunk due to factors like androgenetic alopecia [1.3.4, 1.3.2]. If an area of the scalp is completely bald and the follicles are gone, minoxidil will not be effective [1.3.2]. Its success lies in acting on follicles that are still present, albeit in a miniaturized or resting state.

How Minoxidil Actually Works: The Pharmacological Mechanism

Originally developed as a treatment for high blood pressure, minoxidil's hair-growing properties were a notable side effect [1.3.2]. Its exact mechanism is complex and not fully understood, but it is known to be a vasodilator and a potassium channel opener [1.2.2].

Here’s how it impacts hair growth:

Increased Blood Flow (Vasodilation): Minoxidil widens blood vessels in the scalp, which increases the flow of blood, oxygen, and nutrients to the hair follicles [1.2.2, 1.3.2]. This enhanced nourishment helps to support and stimulate follicle activity.
Potassium Channel Opening: By opening potassium channels in hair follicles, minoxidil may help hyperpolarize cell membranes, which is thought to stimulate and prolong the anagen (growth) phase of the hair cycle [1.2.2, 1.4.2].
Stimulation of Growth Factors: Research indicates minoxidil can induce the expression of Vascular Endothelial Growth Factor (VEGF), which aids in the vascularization process around follicles, promoting hair growth [1.2.1].

The Hair Growth Cycle and Minoxidil's Influence

To understand minoxidil's effect, it's crucial to know the hair growth cycle, which consists of three main phases:

Anagen (Growth Phase): The active phase where hair grows. This phase can last for several years [1.4.5]. Minoxidil helps to extend the duration of this phase [1.4.2].
Catagen (Transitional Phase): A short phase where the hair follicle shrinks and detaches from the dermal papilla [1.4.5].
Telogen (Resting Phase): The follicle is dormant for a few months before the cycle repeats [1.4.5]. Minoxidil is effective at shortening this resting phase, pushing follicles prematurely back into the anagen phase [1.4.1, 1.4.2].

This manipulation of the hair cycle is why users often experience an initial shedding period, commonly known as the "dread shed." As minoxidil pushes many resting hairs into the growth phase simultaneously, it first causes the old hairs to fall out [1.7.1, 1.7.3]. This shedding typically begins 2-8 weeks after starting treatment and is a temporary sign that the medication is working [1.7.1, 1.8.1].

Minoxidil vs. Finasteride: A Comparison

Minoxidil is often compared to finasteride, another popular hair loss treatment. However, they work in fundamentally different ways. Finasteride is a 5-alpha reductase inhibitor, meaning it blocks the conversion of testosterone to dihydrotestosterone (DHT), the hormone primarily responsible for shrinking hair follicles in androgenetic alopecia [1.5.2, 1.5.3].


Feature	Minoxidil	Finasteride
Mechanism	Vasodilator; stimulates blood flow and extends the growth phase [1.5.5].	5-alpha reductase inhibitor; blocks DHT production [1.5.2].
Application	Topical (foam/liquid) or Oral (off-label) [1.5.2].	Oral tablet [1.5.2].
FDA Approval	Topical versions approved for men and women [1.5.2].	Approved for men only; not for use by pregnant women [1.5.2].
Primary Goal	Strong at encouraging regrowth [1.5.1].	Strong at preventing further hair loss [1.5.1].
Common Side Effects	Scalp irritation, dryness, initial shedding [1.6.2]. Oral use can cause hypertrichosis (excess body hair), dizziness, and fluid retention [1.6.3].	Sexual side effects (decreased libido, erectile dysfunction) and potential mood changes [1.5.2].

For many, combination therapy using both minoxidil and finasteride is more effective than using either alone, as they target hair loss from two different angles [1.5.3].

Oral vs. Topical Minoxidil

While topical minoxidil (like Rogaine®) is applied directly to the scalp, low-dose oral minoxidil is increasingly used off-label. Oral minoxidil is metabolized more efficiently by the liver, which can lead to more consistent effects for individuals who don't respond well to the topical form [1.6.1]. However, oral minoxidil has a higher risk of systemic side effects, such as hypertrichosis (unwanted hair growth on the face and body), fluid retention, and a fast heart rate [1.6.3, 1.6.4]. Topical versions are more likely to cause localized scalp irritation [1.6.5].

What to Expect: Timeline, Results, and Discontinuation

Initial Results: The first signs of reduced shedding and new, soft vellus hairs can appear after about 8 weeks of consistent use [1.2.1, 1.8.4].
Peak Results: More significant results, with thicker and longer hair, typically manifest around 4 to 6 months [1.4.2, 1.8.3].
Discontinuation: Minoxidil is a treatment, not a cure. Its benefits are only sustained with continuous use [1.10.1]. If you stop using minoxidil, the hair follicles will revert to their pre-treatment state, and any regrown hair will likely be shed within 3 to 6 months [1.10.1, 1.10.2].

Conclusion

So, does minoxidil cause hair follicles? No, it doesn't create new ones. It works by stimulating dormant follicles, widening blood vessels to improve nutrient supply, and prolonging the hair's growth phase. It's a powerful tool for slowing hair loss and promoting regrowth in existing follicles, especially when started early. Understanding its mechanism, the initial shedding phase, and the need for continuous use are key to managing expectations and achieving the best possible results.

For more information on hair loss treatments, consult a board-certified dermatologist. An authoritative source for patient information is the American Academy of Dermatology.

Disclaimer: This article is for informational purposes only and does not constitute medical advice. Consult with a healthcare professional before starting any new treatment.

American Academy of Dermatology - Hair Loss

Frequently Asked Questions

No, there is no evidence that minoxidil can revive dead hair follicles. It works by stimulating existing follicles that are dormant or miniaturized, but it cannot regrow hair once a follicle is completely gone [1.3.1, 1.3.2].

The initial shedding phase, or 'dread shed,' typically starts within the first few weeks of treatment and lasts for about 2 to 8 weeks. It is temporary and usually a sign that the treatment is effective [1.7.1, 1.8.1].

If you stop using minoxidil, the benefits will reverse. The hair follicles will return to their previous state, and any hair that was gained or maintained will likely fall out over the course of 3 to 6 months [1.10.1].

Oral minoxidil can be more effective for some individuals because it's more consistently absorbed and activated by the liver. However, it also has a higher risk of systemic side effects like unwanted body hair growth, whereas topical minoxidil's side effects are usually limited to scalp irritation [1.6.1, 1.6.3].

Yes, using minoxidil and finasteride together is often more effective than using either one alone. They work through different mechanisms—minoxidil stimulates growth while finasteride blocks DHT—providing a comprehensive approach to treating hair loss [1.5.3].

Initial results, such as a decrease in hair shedding or the appearance of soft, new hairs, can be seen after about 8 weeks. More noticeable results in hair thickness and length typically take 4 to 6 months of consistent daily use [1.4.2, 1.8.3].

Minoxidil can work for a receding hairline, but with a major caveat: it is effective on areas where hair follicles are thinning or dormant, not where they are completely gone. It's most effective when used early to prevent further recession and potentially promote some growth at the edges of the hairline [1.3.2].