Can Melatonin Cause Acne? Side Effects of Melatonin

I’ve had acne since my teens, but it was always mild. Never cystic. Never nodular. And then suddenly, my jawline started exploding.

Deep, painful breakouts. One after the other. I changed the water. Switched cleansers. Stopped using my usual moisturizer. Cut down dairy. Blamed the mask I was wearing all day. Nothing helped.

I was treating all the symptoms with my regular skincare actives, but I couldn’t find the cause. And mentally, it was exhausting. Because when your skin is your job (I am a dermatologist), and it’s falling apart in front of your eyes, you start doubting everything.

Until one day, it just clicked.

A few weeks before all this started, my sleep had gone completely off track. We had just moved to the UAE. New country, new apartment, new job, everything hectic. I was barely sleeping.

A colleague had suggested Melatonin. A supplement available OTC where I live now. And I didn’t think much of it. But then, it struck me: What if it’s the melatonin? After all, melatonin isn’t just a sleep aid, it’s a hormone. Could it be causing my acne? Let’s investigate…

What Exactly Is Melatonin (MLT)?

Melatonin, often shortened to MLT, is widely known as the miracle hormone that regulates sleep and circadian rhythm “naturally” without causing “addiction.”

It’s a potent antioxidant and a cytoprotective agent, helping cells combat oxidative stress (the damage caused to your body responsible for wear-and-tear and aging.

In fact, its antioxidant action is so good that currently it is also being use topically in the cosmetics industry for skin pigmentation and “rejuvenation”.

Studies suggest melatonin may play a role in managing conditions like hypertension, diabetes, gastrointestinal diseases, and even certain cancers (too much of a stretch if you ask me).

Despite these ‘promising’ uses, there’s a big gap in research that I just discovered:

VERY FEW randomized, double‑blind, placebo‑controlled trials have looked at the side effects of melatonin (which I believe has much to do with its “natural” status).

Scientists are still learning how melatonin’s receptors (MT1 and MT2) act outside the brain, in so‑called peripheral systems like the skin. A meta‑analysis  (the highest level of research that combines results from many studies to give the most reliable evidence) found that skin irritation is a noted side effect.

How Could Melatonin Trigger Acne?

After scouting a ton of research papers, I found out that research is limited, but here are some possible mechanisms:

1. Hormonal effects

Melatonin interacts with other hormones. Some studies show it can influence androgen levels (such as testosterone), which directly affect sebum production and acne formation. For most people this is neutral or beneficial, but in someone prone to hormonal acne (exhibit A: Yours truly), even a small shift can trigger breakouts.

2. Skin barrier and sebum regulation

Skin cells themselves produce and respond to melatonin. Supplemental melatonin could theoretically disrupt this balance and overstimulate sebum production in certain individuals.

3. Inflammation

Melatonin is generally anti‑inflammatory, but in some contexts, altering immune responses may paradoxically worsen inflammation in acne‑prone skin.

Evidence From the Literature

There aren’t many reports, but a published case report describes a 33‑year‑old woman who developed acneiform eruptions after starting melatonin 3 mg daily. She had no prior history of such acne. After stopping melatonin, her skin cleared.

This aligns with what I experienced personally.

When I read that? My jaw hit the floor. That was exactly what I was going through.

Evidence From My Clinic

This happened to me around two months ago, and yep, I’m still recovering. I still have a few scars, but you know… dermatologist privilege. Nothing that couldn’t be fixed with retinoids, a few sessions of chemical peel and sun protection.

But this next part really made me sit up:

Since then, I’ve been asking more questions when patients come in with sudden unexplained cystic acne.

And… drumrolls

I’ve already seen three patients (all in their 20s and 30s) with the exact same pattern:

Sudden, deep, nodular jawline acne.

No PCOS.

No new skincare or diet changes.

No other hormonal issues.

All of them had one thing in common… they were taking melatonin.

Two were taking it because of night shifts; one because she’d been traveling and couldn’t reset her sleep.

None of them suspected it.

And in all three, once they stopped melatonin, their skin started calming down.

So, Should You Be Worried?

Look, melatonin is safe for most people. Millions take it without a single breakout.

But if:

A. you’re prone to acne,

B. you suddenly develop unexplained cystic breakouts after starting melatonin, and 

C. you’ve ruled out the usual suspects (skincare, diet, stress, environment),

…it might be worth considering the supplement as a possible culprit.

Assuming anything labeled “natural” as harmless has become a knee-jerk response for most of us, which might not always be a good thing.

I’ll keep updating as I learn more, but for now, if your skin is flaring without explanation, don’t forget to look at everything you’re putting in your body.

Even the things you thought were safe.

Have you experienced skin changes with melatonin? Share your thoughts. I’d love to hear your experiences and compare notes.