Professor Caitriona Ryan, Consultant Dermatologist and Co-Founder of the Institute of Dermatologists, joined Ciara Kelly on Newstalk's The Hard Shoulder to talk about a condition that catches a lot of people off guard: acne that shows up, or comes back, well into adulthood.

Adult acne is far more common than most people realise, affecting up to a fifth of adult men and over a third of adult women. It tends to concentrate on the lower face, jawline and neck, often flares in the week before a period, and is driven by genetics and hormones, not diet or stress. Treatment ranges from topical products for mild cases to hormonal treatment or isotretinoin for more persistent or scarring acne.

What Does Adult Acne Look Like?

According to Professor Caitriona Ryan, adult acne presents in a broadly similar way to teenage acne, the same red and yellow bumps, but the pattern and location are often different.

"It does present pretty similar to teenage acne, but when you see it, typically in women, it is more lower face," she explained. "You're seeing the same pimples, so red bumps, yellow bumps, and then, often when it's adult hormonal acne, larger cysts."

Those cysts are the detail worth paying attention to. Unlike smaller surface spots, they can scar, and in women the pattern often has a monthly rhythm. "In that premenstrual week, the week before a period, they can often get really bad," Professor Ryan noted. "Women often dread this part of the month if they're suffering from adult hormonal acne."

Why Do So Many Women Get Hormonal Acne as Adults?

Adult acne is significantly more common in women than men, and it frequently appears for the first time well after the teenage years.

"I've had lots of women who had spotless skin until their 20s, and then adult hormonal acne kicked off," Professor Ryan said. One of the reasons it's often taken less seriously, by patients and sometimes by the people around them, is that it can look like a minor, occasional flare rather than a persistent condition. "They've got this sort of grumbling acne that never goes away, so they're at the mercy of it. And, of course, it always turns up when you've got a big event the following day, or for some women, on their wedding day."

Is Adult Acne Caused by Diet or Stress?

No, and Professor Ryan is direct about this: the first thing she tells patients is that adult acne is not something they've caused.

"I think a lot of people blame themselves, they say it's my diet or it's because I'm so stressed," she said. "Those things can have a little bit of an effect, but only if the acne is there in the first place. If you're eating a diet really high in glycaemic load, it can worsen it, but it is not the cause. The cause is genetics and hormonal influences."

What's the Right Treatment for Adult Acne?

Professor Ryan describes a clear step-up approach, starting simple and escalating only when needed.

For mild acne or congestion, topical treatment alone is often enough, and she's wary of patients overspending before trying the basics. "So many women go and spend a fortune on really expensive skincare, or go for procedures, when they have a medical problem and need to see their GP," she said. A GP can then refer on to a dermatologist if the acne is more severe.

For more persistent or hormonal acne, especially where cysts are forming or there's any sign of scarring, an oral antibiotic may be used for an occasional flare, but hormonal-type acne "doesn't typically just go away, it persists until it's treated properly." From there, the two main options are hormonal treatment and isotretinoin.

On the contraceptive pill: "It can work very well in some people, but you never want somebody to be on the pill just for their acne, because when they eventually come off, especially if they want to start trying for a baby, it all just comes back again. It never cures it, it just controls it while they're on it." 

Where there's any evidence of scarring, Professor Ryan has a low threshold for moving to isotretinoin (brand name Roaccutane), which she considers the more permanent fix.

Isotretinoin (Roaccutane): What About the Depression Concerns?

This is the question Professor Ryan often gets asked.

"It's an amazing drug, but a drug that needs to be respected," she said. "For the vast majority of patients, they do fantastically. Pretty much everyone clears, about 70% of people are clear forever. The most regret patients have is that they didn't start it years, sometimes decades, beforehand."

There are two genuine side effects to be aware of. The first is pregnancy risk: isotretinoin is a synthetic form of vitamin A, which is toxic to a developing foetus, so patients need to be on adequate birth control while taking it. The second is depression, which Professor Ryan says is rare but real. "I've seen four cases in my career, out of thousands of patients. And the good news is, when you look at the big database studies, the systemic reviews, they actually show that patients on isotretinoin, compared to antibiotics, have less depressive symptoms. Not because isotretinoin treats depression, but because treating someone's acne treats their depression."

She points to the wider impact severe acne can have at a formative age, on confidence, social life, even career choices, as the reason that link runs the way it does.

Frequently Asked Questions

Can acne really start for the first time in your 30s or 40s?

Yes. Adult hormonal acne often appears for the first time well after the teenage years, sometimes even after a decade or more of clear skin.

Does the contraceptive pill cure hormonal acne?

No. It can control hormonal acne effectively while a woman is taking it, but it doesn't treat the underlying cause, so acne typically returns once the pill is stopped.

Will changing my diet clear up adult acne?

Diet is unlikely to be the cause, though a very high-glycaemic-load diet can make existing acne worse. The underlying driver is genetics and hormones.

Is Roaccutane (isotretinoin) safe?

For most patients, yes, with about 70% seeing their acne clear permanently. It carries two known risks: it must not be taken during pregnancy, and in rare cases it has been linked to low mood, which is monitored closely during treatment.

When should adult acne be treated by a dermatologist rather than managed with skincare?

When there are cysts, any sign of scarring, or acne that keeps recurring despite topical treatment. A consultation with a GP or in more severe cases, a referral to a dermatologist is the right next step at that point, rather than continuing to manage it alone.

Why Does Acne Scarring Matter?

Cystic, hormonal acne is the type most likely to leave lasting marks, and once scarring has happened, skincare alone won't reverse it. That's part of why Professor Ryan has a low threshold for moving to isotretinoin when cysts are forming, treating the acne itself is what prevents the scarring in the first place.

This article is based on Professor Caitriona Ryan's interview on 2nd September 2026 The Hard Shoulder with Ciara Kelly, Newstalk, discussing how best to manage adult acne.