IPL and hormones: why hair grows back and what you can do about it

You faithfully use IPL, first see less hair growth, and then suddenly hairs reappear. Frustrating, especially when you thought you were "done" with it. Anyone searching for "IPL hair reduction" often encounters quick claims. However, the reality is more nuanced.

IPL works on existing hairs in the correct growth phase. Meanwhile, hormones can stimulate new hair growth. That doesn't immediately mean IPL doesn't work. It mainly means your body is not a static system. In this blog, you'll read why hair growth returns, what role hormones play, and how to maintain your IPL results as effectively as possible.

What is IPL hair reduction?

IPL hair reduction means that light pulses are converted into heat via pigment in the hair, weakening the hair follicle and reducing growth over time. IPL stands for Intense Pulsed Light.

The technique primarily targets melanin: the pigment in dark hairs. Therefore, IPL usually works best on light to medium skin with dark blonde, brown, or black hair. Very light blonde, red, gray, or white hair contains little pigment, which means the light cannot be absorbed as effectively.

An important point: IPL does not treat all hairs at once. Hair grows in phases. The active growth phase, in particular, is sensitive to light treatment. IPL works when a hair is in the growth phase because the hair root is then sensitive to pulsed light.

That's why you need multiple sessions. Not because IPL is "weak," but because your hair cycle is spread out. This also explains why stubble returns faster in some places than in others.

How do IPL and hormones work in practice?

Imagine: you treat your legs diligently according to schedule for eight weeks. The hairs become softer, grow back slower, and some areas remain smooth for longer. Then, after a few months, you notice some stubble again.

This can have three causes.

Firstly, hairs that were previously in a resting phase may become active later. These were less effectively targeted during earlier sessions. Secondly, maintenance may be necessary because IPL reduces hair growth but does not always stop it permanently. Laser hair removal is a method that can significantly reduce hair growth, but hair may return over time and maintenance is sometimes required.

Thirdly, hormones play a role. Hormones can effectively "switch on" hair follicles. This is more often seen in areas sensitive to androgens, such as the chin, upper lip, neck, abdominal line, nipples, and bikini line.

During hormonal fluctuations, your body can therefore produce new hairs, even if previous hairs responded well to IPL.

Why does hair growth return after IPL?

Hair growth returning after IPL is usually not a sign that it was all in vain. Often, it involves fewer, finer, or lighter hairs. Sometimes it only seems like "everything is back" because you pay extra attention to every new hair.

Nevertheless, there are situations where hair growth clearly returns stronger. Consider:

• stopping or changing contraception;
• pregnancy or the postpartum period;
• menopause or perimenopause;
• PMOS (formerly PCOS);
• increased androgens;
• stress and lack of sleep;
• predisposition to dark, coarse hair.

For PMOS and hirsutism, laser or light treatment can help, but the results may be less predictable. A study in women with PMOS found that laser treatment was associated with a less significant reduction than expected. A medical review on hirsutism also notes that maintenance and combination with treatment of underlying causes can be important.

Important: IPL treats the visible symptom, namely hair growth. It does not change your hormone balance.

Who is IPL suitable for and who is it less suitable for?

IPL is particularly suitable for people with sufficient contrast between skin and hair. Dark hair on light to medium skin usually responds best. With little pigment in the hair, the effect is limited.

It is better not to use IPL without medical advice during pregnancy, active skin infections, suspicious spots, recent sunburn, certain medications, or skin conditions. When in doubt, a doctor or skin therapist is the safest route.

Common misconceptions about IPL hair reduction

"If hair grows back, IPL didn't work"

Not necessarily. IPL may have weakened previous hairs, while new hairs become active later. This is normal, especially in hormonal areas.

"After one course, you're done forever"

That's too absolute. The American Academy of Dermatology states that most people see some hair regrowth and that maintenance treatments may be necessary.

"IPL works the same on every body part"

No. Legs and underarms often respond more predictably than the face, chin, or neck. The AAD indicates that facial laser hair removal in women is less permanent due to hormones than on many body parts.

"More flashes mean faster results"

Treating too often doesn't automatically help. Hairs need to be in the correct growth phase. Treating too intensely can irritate the skin.

Practical tips for maintaining IPL results

Start with a fixed schedule. Follow the recommended build-up phase of your device and don't skip treatments. Consistency is more important than haste.

Shave before your IPL session. Do not wax or epilate, as this removes the hair root needed to conduct the light.

Protect your skin from the sun. Do not treat sunburned or heavily tanned skin. This increases the risk of irritation.

Plan for maintenance. After the build-up phase, many people need a maintenance session once every few weeks or months. How often depends on your hair growth, skin type, area, and hormones.

Pay attention to hormonal signals. Do you suddenly experience much coarser hair growth on your chin, neck, chest, or abdomen? Or do you also have acne, irregular menstruation, or hair loss on your head? Discuss this with your GP.

An IPL device with a skin tone sensor can help to better adjust the intensity to your skin. The Laesera Nova One fits into such a routine for those who want to treat quietly and consistently at home, without exaggerated claims of results.

Frequently asked questions about IPL hair reduction

Can hormonal hair growth disappear with IPL?

IPL can reduce hormonal hair growth, but it does not address the hormonal cause. As a result, new hairs can continue to appear. Maintenance is often necessary, especially for the chin, upper lip, neck, and bikini line.

Why does hair growth return after IPL?

This is usually due to the hair growth cycle, the need for maintenance, or hormonal influence. Hairs that were previously in a resting phase may become active later. Hormones can also stimulate new hair follicles.

Does IPL work for PMOS?

IPL can help reduce visible hair growth in PMOS (formerly PCOS), but results are less predictable. More sessions and maintenance are often needed. Always discuss severe or sudden excessive hair growth with a doctor.

How do I maintain my IPL results?

First, follow the full build-up phase. Then schedule maintenance sessions as soon as you notice hair returning. Shave beforehand, avoid sun exposure around treatments, and do not treat more often than recommended.

Is returning hair growth after IPL normal?

Yes, some regrowth is normal. The goal of IPL is long-term hair growth reduction, not a guarantee that no hair will ever grow again. Hairs often grow back finer, lighter, or slower.

Conclusion

IPL can visibly reduce hair growth, but hormones can influence the result. Especially hormonal areas often require more patience and maintenance. Therefore, returning hair growth does not automatically mean that IPL does not work. It means that your routine must fit your body, your hair cycle, and any hormonal factors.

A realistic approach usually yields the best results: consistent treatment, gentle care for your skin, and an honest assessment of what your body needs.