Understanding the 'Dread Shed': Why does hair shed when using minoxidil?

October 11, 2025 •

4 min read

Over 18% of minoxidil users experience an initial phase of increased hair shedding, often called the “dread shed”. So, why does hair shed when using minoxidil, and is this temporary side effect a normal part of the process? The shedding is an expected and temporary part of treatment, indicating that the medication is actively working to reset your hair’s growth cycle and make way for new, healthier strands.

Quick Summary

Minoxidil accelerates the hair growth cycle, causing resting-phase hairs to shed more rapidly to make way for new, stronger growth. This initial, temporary increase in hair loss is a positive sign that the treatment is effective. The phenomenon is short-lived, typically subsiding within a few months as new hair begins to grow.

Key Points

Minoxidil accelerates the hair growth cycle: The medication pushes hair follicles from the resting (telogen) phase into a new, active growth (anagen) phase faster than usual.
Shedding is a sign the treatment is working: Increased hair fall is an indicator that your follicles are responding to the medication and clearing out old hairs.
The "dread shed" is temporary: The shedding phase typically begins a few weeks after starting treatment and resolves within 4-6 months as new, healthier hair grows in.
Shedding can be synchronized: Minoxidil can cause many hair follicles to reset their cycle at once, leading to a noticeable, though temporary, increase in shedding.
Consistency is key during the shedding phase: Do not stop using minoxidil during the shed, as this will interrupt the treatment and may prevent new growth.
Manage expectations: Understand that the shed is a short-term phase on the path to long-term hair regrowth.
An allergic reaction is different from shedding: Irritation, redness, and itching could indicate a reaction to an ingredient like propylene glycol, not the normal shedding process.

The Science Behind Minoxidil Shedding: Resetting the Hair Growth Cycle

When you begin using minoxidil, it might seem counterintuitive to see an increase in hair fall. However, this is a normal and temporary side effect, widely known as the “dread shed”. The shedding happens because minoxidil works by manipulating the natural hair growth cycle, a complex process that every hair follicle on your scalp goes through. For those with androgenetic alopecia, this cycle becomes disrupted, with the anagen (growth) phase shortening and the telogen (resting) phase lengthening, leading to progressively thinner hairs.

Minoxidil's key action is to reverse this trend. It acts as a vasodilator, increasing blood flow and nutrients to the follicles. This revitalizing effect forces the hair follicles that have been stuck in a prolonged telogen phase to rapidly move into the exogen (shedding) phase. The older, weaker hairs are pushed out to make room for the new, stronger hairs that will grow in their place during an extended anagen phase.

This synchronized shedding can be alarming, but it is a strong indicator that the treatment is working effectively. It’s essentially a reset button for your hair follicles, clearing out the old to make way for the new. The shed hairs were likely already weak and destined to fall out, but minoxidil simply accelerates the process.

Hair Growth Cycle Phases

To better understand how minoxidil causes shedding, it's helpful to review the four phases of the hair growth cycle:

Anagen (Growth Phase): This is the active growth phase, which can last for several years. Minoxidil works to prolong this phase, promoting longer and thicker hair growth.
Catagen (Transition Phase): A short transition period lasting a few weeks where the hair follicle shrinks and hair growth stops.
Telogen (Resting Phase): This phase typically lasts about three months. The hair is fully formed but is not actively growing. Minoxidil significantly shortens this phase.
Exogen (Shedding Phase): The final stage where the old hair detaches and falls out to allow the new anagen hair to emerge. Minoxidil accelerates this step by pushing hairs from telogen into exogen at a more rapid rate.

This is why the initial burst of shedding occurs—many hairs are transitioning from the resting phase to the shedding phase at the same time, a process known as follicular synchronization.

Timeline and Duration of Minoxidil Shedding

For most users, the dread shed follows a predictable timeline. It's crucial to be patient and stick with the treatment to see results.

Weeks 2-4: Shedding may begin, though it might be minimal and not noticeable to everyone.
Weeks 6-12: Shedding often peaks during this period as the follicles reset their cycles.
Weeks 12-16: The shedding gradually subsides, and the initial signs of new growth may become visible.
Months 4-6: For most, shedding returns to baseline levels, and new, healthier hair growth becomes more evident.

If shedding continues excessively beyond four to six months, it’s advisable to consult a dermatologist to rule out other potential causes.

Minoxidil Shedding vs. Allergic Reaction

It is important to differentiate between the normal minoxidil shedding and a potential allergic reaction, which is less common but can occur.


Feature	Minoxidil Shedding	Allergic Reaction (e.g., to Propylene Glycol)
Mechanism	Hair cycle reset, pushing resting hairs to shed.	Inflammatory response to an ingredient, causing skin irritation.
Symptoms	Increased hair fall, which should be temporary.	Scalp irritation, redness, itching, burning sensation, or eczematous reactions.
Timing	Starts 2-8 weeks into treatment and typically ends by 4-6 months.	Can occur soon after starting use and may persist or worsen.
Treatment	Continue use; it resolves on its own.	Stop using the product and consult a doctor. May switch to a different formulation, like foam without propylene glycol.

If you experience significant itching, redness, or discomfort, it is crucial to consult your doctor, as this may indicate a reaction to an ingredient like propylene glycol.

Coping with the Dread Shed

Seeing more hair in your brush or shower can be stressful, but remember that this is a temporary and necessary step toward regrowing healthier hair. Here are some tips to help you through this phase:

Stay Consistent: It is vital to continue using minoxidil as directed without skipping doses. Inconsistent application can disrupt the cycle and prolong the shedding.
Be Patient: Understand that minoxidil is a long-term treatment. Focusing on the end goal of healthier hair can help you push through the initial shedding period.
Manage Expectations: Knowing the timeline and that shedding is a sign of progress can reduce anxiety. Most people see peak shedding around weeks 6-12.
Focus on Other Hair Care: Supplement your routine with gentle shampoos and nourishing products to support overall hair health. Biotin and other supplements may also help maintain strand strength.
Consider a Different Formulation: If you suspect an irritant reaction to the propylene glycol in the solution, consider switching to the foam version of minoxidil, which does not contain this ingredient.

Conclusion

Minoxidil-induced hair shedding, or the “dread shed,” is a well-documented and normal side effect of starting this hair loss treatment. It occurs because minoxidil accelerates the hair growth cycle, pushing older, weaker hairs out to make way for new growth. This temporary phase is a positive sign that the medication is working. While the increased hair fall can be distressing, consistency is key, and patience will be rewarded as new, thicker hair starts to grow in after a few months. Should the shedding be excessive or persist beyond the expected timeline, or if you experience significant irritation, consult a healthcare professional to rule out other issues.

For more detailed information on minoxidil and its effects, you can visit the National Institutes of Health (NIH) website for resources like this study on minoxidil's efficacy: https://pubmed.ncbi.nlm.nih.gov/29494000/.

Frequently Asked Questions

Yes, minoxidil shedding is typically considered a good sign. It signals that the hair follicles are responding to the treatment, actively resetting their growth cycle, and preparing to grow new, stronger hair.

The duration of minoxidil shedding varies, but it typically starts within the first 2 to 8 weeks of treatment and can last up to 4 months. For most people, it peaks between weeks 6 and 12 and then gradually subsides.

You cannot prevent the initial minoxidil shedding, as it is a natural part of how the medication works by accelerating the hair growth cycle. It is a sign of an effective treatment rather than an adverse effect to be avoided.

No, you should not stop using minoxidil when you start shedding. Stopping can interrupt the treatment and reverse any progress made. Consistency is crucial for the medication to be effective over time.

Yes, some people might confuse the two. An allergic reaction typically involves persistent scalp irritation, redness, and itching, often caused by an ingredient like propylene glycol. In contrast, shedding is simply an increase in hair fall without other inflammatory symptoms.

If excessive shedding continues for more than 4-6 months, it is best to consult a dermatologist. Persistent shedding may be due to other underlying causes or an indication that the treatment is not working as expected.

No, the shedding phase does not mean all your hair will fall out. It is a temporary, concentrated shedding of older, weaker hairs to make room for new, stronger ones. The overall outcome, with consistent use, is increased hair density and thickness.