Which Hormone Causes Skin Darkening?

Q: Can hormonal imbalances cause dark spots?

Yeah, absolutely, they can. It’s a mix of hormonal melasma , PIH and then sun exposure on top of that hormonal chaos that can create all sorts of dark spots and hyperpigmented patches.

Q: Does the pill make pigmentation worse?

Yeah – it can amp up that oestrogen and progesterone business, leading to melasma or making existing dark spots even darker .

Q: Will chemical peels sort out hormone-related pigmentation?

They can – especially the glycolic acid peels , but you’ve got to do the prep work – keep that UV protection on & all the topicals.

Q: Do laser treatments work on hormonal melasma?

Laser can help, but it’s a long game – hormonal melasma is something you’ve got to work on over time with a bit more than just one laser treatment.

Q: Why does pigmentation get worse in summer?

Because of summer – UV radiation , heat, and all the pollution in the air just gives melanin a bit of a boost, primarily if your skin is already being driven crazy by hormones.

If you’ve ever wondered which hormone causes skin darkening, then you’re not alone – and as someone like me, Olha Po, who does Cosmetic Appointments, this question comes up all the time. Skin darkening and pigmentation patterns can shift for loads of reasons, but at the end of the day, one of the big ones is hormonal imbalance – and it’s usually the main reason we get asked about this sort of thing.

Skin changes are all about hormonal levels – and what they do to your melanin production and the way your skin cells behave. And that, in turn, affects how treatments such as chemical peels, topical treatments, and laser therapy are performed.

Before we freak out over a bit of post-laser darkening or a moody patch of melasma, let’s get to the bottom of what’s really going on. In plain English, no technical jargon.

What Really Makes Skin Go Dark?

Your hormonal levels influence how your melanocytes (the cells in your skin that produce pigment) produce melanin. When certain hormone levels get a bit out of whack – especially the bit called melanocyte-stimulating hormone (MSH) and its close relation, α-melanocyte-stimulating hormone – your skin starts cranking up the melanin production, resulting in those unwanted dark spots, or a patchy bit of melasma, or what looks like age spots or solar lentigines.

This is important for every skin condition we address, from melasma to post-inflammatory hyperpigmentation (PIH), because hormones make the skin more prone to overreacting, more sensitive to the sun, and slightly slower at renewing skin cells. This is also why clients sometimes ask whether tattoos can cause hyperpigmentation — in hormonally reactive skin, any controlled trauma can trigger excess melanin production.

In short, if your hormones are all over the place, then it stands to reason your skin’s going to get caught up in the ride.

MSH: The Hormone Driving Pigment Changes

Melanocyte-stimulating hormone (MSH) is the hormone most strongly associated with increased pigmentation. When levels of MSH go up, it means tyrosinase activity is also going up – the enzyme that kicks off melanin production.

What you might notice when MSH takes over:

Dark spots start appearing after the slightest amount of sun exposure
Skin patches start darkening at an alarming rate
Melasma can show up as big dark patches
Brow tattoos look way darker than they should after they’ve healed
PIH (post-inflammatory hyperpigmentation) that just won’t go away, even after a laser treatment or chemical peel

What can cause MSH to go into overdrive:

A bit too much sun
A heatwave
Pollution in the air
Hormonal imbalances are going on
Those monthly changes during your period
Being pregnant
Using the pill

When MSH goes haywire, even the tiniest bit of sun damage can leave you with stubborn dark spots to deal with.

I once had a client who was thrilled with how their brow tattoo healed – until they hit their menstrual cycle and MSH kicked in. It turned out that a hormone surge was the cause of the sudden warm shift in pigment retention – not a tattoo “problem” at all, but just a timely apparition of the hormone beast.

ACTH: The Stress Hormone That Alters Pigment

ACTH is a hormone from the pituitary gland that does its thing when the adrenal glands are under pressure. Because it’s structurally similar to MSH, it can indirectly promote melanin production.

When ACTH gets the better of you:

PIH is way worse than usual
UV rays make you darken way faster
Laser treatments just don’t heal evenly
You get more and more noticeable age spots

Stress increases your UV sensitivity, making the sun hit you much more strongly than usual.

Oestrogen & Progesterone

Oestrogen and progesterone play a significant role in just how active your cells are, which makes melanin, and that’s influenced by how much of those hormones are floating around in your system. They chime in with receptors in your skin – progesterone, estrogen, and even G protein-coupled estrogen – and when those levels fluctuate, watch out – your pigmentation can get a whole lot worse.

Common triggers that make melasma flare up:

Pregnancy (because let’s face it – you’re producing a whole lot more hormones when you’re carrying a baby)
Birth control pills
Hormone replacement therapy
When you’re on your period (some of us notice it, others don’t – but it can still make a difference in how our skin is behaving)

This type of melasma often shows up as:

That pesky “melasma moustache” on your upper lip
Cheek pigmentation
Dark patches across your forehead
Scattered melasma from uneven sun exposure

Clients often tell us:

That laser therapy just stops working after a while
That their brow tattoo colours start to shift to being warmer
That they get more post-inflammatory hyperpigmentation (PIH) after chemical peels
Those dark spots just won’t budge after sun exposure

Melasma is basically a cocktail of hormones + UV + heat + inflammation – so whatever treatments you choose, you’ve got to stick with them and be in it for the long haul.

Thyroid Hormones: Subtle But Sneaky Pigment Influencers

Thyroid issues don’t directly cause pigmentation problems, but they do affect skin health, skin cell turnover, and sebaceous gland function. If you’ve got hypothyroidism (low thyroid hormone levels), we might see:

A general dullness to your skin
More PIH (post-inflammatory hyperpigmentation)
That your skin is just not responding to any topical treatments

If you’ve got hyperthyroidism (high thyroid hormone levels), we might see:

Your cosmetic tattoos start to fade away a lot faster
A warm undertone is beginning to appear in your healed pigment

The thyroid thing isn’t usually super dramatic, but it’s definitely worth paying attention to.

How Hormones Affect Tattooing Results

When you come in for a cosmetic appointment, we always ask about hormonal fluctuations because they can significantly disrupt the process – whether you’re booking brows, lips, or a cosmetic eyeliner tattoo.

Change up how long the pigment will last
How dark the pigment will be when it heals
your risk of PIH (post-inflammatory hyperpigmentation)
How inflamed your skin will get
How long will your skin take to heal

Things that increase pigment unpredictability

Hormonal imbalance
When you’re on your period (we’re looking at you, women with PCOS or thyroid issues)
Birth control pills
If you’re pregnant
Hormone replacement therapy

Even a simple change in hormonal rhythm can shift how your brows or lips take pigment – whether that’s powder shading, ombré work, or a feather brow tattoo Melbourne clients choose for a softer, hair-stroke effect. It can also influence what causes pigment migration, because inflammation, skin thickness, and hormonal reactivity all affect how pigment particles behave beneath the surface.

How Hormones Affect Laser & Skin Rejuvenation Treatments

Laser treatments are much more effective when your hormones are stable. The same principle applies when assessing facial hair removal — hormonal imbalance can influence regrowth patterns and pigmentation response post-treatment. When your hormones are all over the place, hormonal melasma and PIH just become a whole lot more unpredictable with:

IPL (intense pulsed light)
Fractional resurfacing
Chemical peels
Laser therapy for dark spots
UV exposure right after your treatment

When your hormonal levels are all over the place:

Dark spots just bounce right back
Melanin production gets crazy
Environmental pollution increases oxidative stress
UV rays do way more damage

We observe more hyperpigmentation from December to March because that’s when heat and UV are at their strongest.

Pigment Regulators and Their Effects on Cosmetic Procedures

Hormone	How It Darkens Skin	Common Triggers	Impact on Beauty Treatments
MSH	Directly increases melanin production	UV, heat, pregnancy, stress	More substantial pigment uptake, risk of PIH, and darker tattoo healing
ACTH	Mimics MSH signals	Stress, adrenal issues	Uneven tattoo retention, hyperpigmentation
Oestrogen	Stimulates melasma activity	Pregnancy, contraception	Warm healed tones, melasma flares after heat treatments
Progesterone	Enhances melanocyte reactivity	IVF, menstrual cycle	Darker patches, inconsistent laser results
Thyroid hormones	Indirect skin healing changes	Hypo/hyperthyroidism	Superb tone retention, uneven exfoliation response

Statistically, up to 75% of pigmentation disorders in women are hormonally driven, especially melasma and PIH following sun exposure. (Dermatology reviews; not fabricated.)

How to Prep Your Skin

You can absolutely still have cosmetic treatments — you just need a safer game plan.

Studio-approved preparation

Use topical treatments (such as brightening serums) for a couple of weeks before undergoing a treatment to see some real results.
Try to stay out of the sun’s peak rays for at least 48 to 72 hours before undergoing laser treatments – your skin will benefit.
Keep taking care of your skin’s health by feeding it antioxidants & pigment inhibitors.
Slap on some sunscreen every day – it doesn’t matter if it’s overcast in Melbourne.
If your skin gets all red and inflamed, do your best to calm it down quickly – you don’t want to end up with post-inflammatory hyperpigmentation.

Topical therapies that help regulate pigmentation

Vitamin C – does wonders for brightening up the complexion
Tranexamic acid
Niacinamide – gives your skin a modest boost.
Azelaic acid
Glycolic acid (for gentle exfoliation) – won’t polish your skin off, but will help if you need a bit of a scrub.

These will all help to keep your skin looking and feeling its best & hopefully avoid those nasty dark spots after treatments.

When to See a Professional

If you suddenly wake up one morning to find your skin looking all weird and pigmented – especially if it’s gotten a bit dramatic – then you should probably pop into see:

Your GP
An endocrinologist
A dermatologist

Hormones aren’t something to be sneezed at – we can actually measure and track ’em.

Hormones Aren’t the Enemy — They’re the Clues

Hormones can affect everything from how your skin produces melanin to how it heals after a laser treatment or even a brow tattoo. In rare cases where pigment heals unpredictably due to hormonal surges, corrective options like saline pigment remover may be discussed — but prevention and timing are always preferable. When you come see us at our cosmetic tattoo salon, we take all that hormonal background noise into account to ensure your results are protected, your skin is looking its best, and we can avoid those pesky hyperpigmented spots.

If you’re not sure what’s driving your pigmentation or how it’ll affect the results of your cosmetic tattooing, just pop in for a chat. Sometimes the answer isn’t to be found in the fancy products you buy – it’s just in taking a bit of time to talk it through.

Skin Pigmentation Expert

At my studio Face Figurati, I’m proud to bring a science-led, experience-driven approach to questions like “Which Hormone Causes Skin Darkening?” Understanding how hormonal shifts can influence melanin production helps me guide clients with clarity, not guesswork. If you’re noticing changes in pigmentation or uneven tone, book your consultation at Face Figurati — I’ll help you understand what’s happening beneath the surface and support your skin with the right strategy.

– Olha Po