HS and Your Menstrual Cycle: Can Your Period Affect Hidradenitis Suppurativa?

If your hidradenitis suppurativa (HS) seems to get worse in the days before your period, you are not imagining something unusual.

It is one of the most consistently reported patterns in the whole of HS research. Study after study finds that people with HS and menstrual cycles describe symptoms worsening around menstruation, and the week before bleeding starts is the timing they name most often.

Two things are equally true, though, and they rarely appear in the same article.

Not everyone with HS experiences cycle-related flaresFlare: A period of acute worsening in a chronic condition. In Acne Inversa, a flare may be triggered by stress, hormonal changes, friction, or other factors and can manifest as new nodules, abscesses, or increased pain.FlareA period of acute worsening in a chronic condition. In Acne Inversa, a flare may be triggered by stress, hormonal changes, friction, or other factors and can manifest as new nodules, abscesses, or increased pain.Read more in the glossary. And a flare that happens around your period does not prove that hormones are the cause of your HS.

This guide covers what researchers have actually found, where the evidence gets thinner than the headline numbers suggest, and — the useful part — how to work out whether the pattern you think you see is repeatable enough to be worth raising at an appointment.

Educational content only. This article describes associations reported in research. It cannot tell you whether hormones are driving your HS, whether you need hormone testing, or whether any hormonal treatment is suitable for you.

Key takeaways

• Menstrual-cycle-related worsening of HS is well documented in patient surveys, and the premenstrual week is the most commonly reported timing.
• Estimates of how many people are affected range from roughly 43% to 96% across studies, which tells you the figure depends heavily on who was surveyed and how.
• The largest and newest figures come from online surveys recruited through HS support networks, where people who have noticed a cycle link are more likely to respond.
• Prospective research that measured symptoms as they happened, rather than asking people to remember, found much less change in objective lesion counts than surveys imply.
• Hormones plausibly play a part, but people with HS do not generally have abnormal blood hormone levels, and the mechanism remains unresolved.
• A pattern that repeats across several cycles is worth documenting and discussing. It is not, on its own, a treatment decision.

How common are period-related HS flares?

There is no single reliable percentage, and you should be suspicious of any page that gives you one.

Here is what the main studies found.

Study	Participants	Reported worsening around menstruation
Fernandez et al., 2020	279 survey respondents	76.7% worsening, 22.2% no change, 1.1% improvement
Collier et al., 2020	283 adults with HS and menstrual cycles	62.4% (176 of 282 answering)
Garrett et al., 2026	255 survey respondents	96.1% reported some cycle-related change

Those are not small differences. They span almost the entire possible range, which is a strong hint that what is being measured is not a fixed property of the disease.

The Collier study adds a useful detail: among the people who did report perimenstrual flares, 86.9% said it happened always or often rather than occasionally. So where the pattern exists, it tends to be a real and recurring feature — not a one-off.

Why the newest study’s 96% is not a population prevalence

The 2026 study published in Skin Health and Disease is the most recent and the most eye-catching. Among 255 respondents, 96.1% reported cycle-related changes in their HS, and 99.6% of those described the change as a worsening.

That number will circulate. It should not circulate as “96% of people with HS flare around their period.”

The survey was distributed online through social media and HS patient-support organisations. Nobody drew a representative sample of people with HS; people opted in. A survey advertised as being about menstruation and HS is exactly the survey that people who have noticed a link are most motivated to complete — and exactly the one that someone who has never noticed a connection is most likely to scroll past.

That is not a criticism of the researchers. It is how patient-reported survey work is usually done, and the study is a legitimate contribution. It just means the percentage describes the people who answered, not everyone with HS.

Read alongside earlier work reporting figures nearer 43–77%, the honest summary is:

Cycle-related worsening appears to be common in HS, and we cannot currently state a prevalence that applies to everyone.

When during the cycle do flares happen?

The most consistent finding across studies is that worsening happens before menstruation begins, not during it.

In the 2020 Collier study, among those reporting perimenstrual flares:

• 78.9% reported flares in the week preceding menses;
• 18.9% during menses;
• 2.3% after menses.

In the 2026 study, among the respondents who noticed cycle-related change:

• 59.2% reported premenstrual worsening;
• 30.2% reported worsening during menstruation.

Smaller numbers in both studies described other timings, including around ovulation or in the week following the period.

The practical point: the premenstrual week is the most common pattern, but it is not the only one, and there is no schedule you should expect your own body to follow. If your worsening lands during your period rather than before it, that is within the range of what people report.

What happens when researchers measure instead of asking?

This is the part most articles on this topic leave out, and it changes how much weight the survey numbers deserve.

Almost all of the evidence above is cross-sectional: someone was asked, at a single moment, to recall how their HS behaves around their cycle. Human recall is not neutral. A painful flare that happened to land two days before a period is memorable and easy to connect; three uneventful cycles are not.

A prospective cohort study presented in 2024 tested this directly. Patients with mild-to-severe HS completed weekly electronic questionnaires for up to 16 weeks, recording menstrual status and whether their lesion count or disease severity had increased since the previous week.

Of the 33 patients enrolled, 23 (70%) said they perceived a link between their symptoms and their cycle — consistent with the survey literature.

But the week-by-week data showed no change in reported flares in the perimenstrual period. That held for the whole group, and it also held when the researchers looked only at the subgroup who believed their HS worsened with menstruation.

Separate research from a group at Duke found something similar with a twist worth understanding. Assessing patients at two defined points in the cycle, they found a statistically significant worsening during menses on validated patient-reported outcome measures — the quality-of-life and symptom scores that capture what the person is experiencing. The clinician-assessed measures — abscessAbscess: An inflamed cavity or swelling containing pus or fluid. In hidradenitis suppurativa, abscesses can form as part of the inflammatory disease process and do not automatically mean that a bacterial infection is present. Secondary bacterial infection can occur and may require separate medical assessment. In Acne Inversa, abscesses occur mainly in the armpits, groin, and other skin folds.AbscessAn inflamed cavity or swelling containing pus or fluid. In hidradenitis suppurativa, abscesses can form as part of the inflammatory disease process and do not automatically mean that a bacterial infection is present. Secondary bacterial infection can occur and may require separate medical assessment. In Acne Inversa, abscesses occur mainly in the armpits, groin, and other skin folds.Read more in the glossary and noduleNodule: A firm, palpable lump deep in tissue. Nodules can be painful and may progress to abscesses. They are among the typical early signs of Acne Inversa.NoduleA firm, palpable lump deep in tissue. Nodules can be painful and may progress to abscesses. They are among the typical early signs of Acne Inversa.Read more in the glossary counts, draining fistulaFistula: A specific kind of tunnel that connects an inflammatory cavity to the skin surface, allowing chronic drainage. In HS literature, 'draining tunnel' and 'fistula' are often used interchangeably.FistulaA specific kind of tunnel that connects an inflammatory cavity to the skin surface, allowing chronic drainage. In HS literature, 'draining tunnel' and 'fistula' are often used interchangeably.Read more in the glossary counts, severity scoring — did not show a significant difference.

Put those together and a more precise picture emerges than either “it’s all in your head” or “96% of women flare”:

• What people experience around menstruation is real and measurable when you measure the experience.
• The visible lesion count may not be what is changing.
• Pain sensitivity, tenderness, swelling, mood, sleep and general inflammatory symptoms all shift across the cycle for many people, with or without HS — and they shape how a flare feels.

None of this means you should dismiss what you notice. It means the honest description of a perimenstrual pattern is usually “my HS feels considerably worse at this point in my cycle” rather than “my HS lesions multiply before my period.” The first is well supported. The second is not.

Why might HS change around menstruation?

Here the evidence gets genuinely thin, and it is worth being upfront about that.

HS is a chronic inflammatory disease centred on the hair follicleHair Follicle: The tube-shaped pocket in the skin from which a hair grows. In Acne Inversa, the follicle becomes plugged and eventually ruptures, spilling its contents into surrounding tissue and triggering the inflammatory cascade that defines the disease.Hair FollicleThe tube-shaped pocket in the skin from which a hair grows. In Acne Inversa, the follicle becomes plugged and eventually ruptures, spilling its contents into surrounding tissue and triggering the inflammatory cascade that defines the disease.Read more in the glossary. Sex hormones have long been suspected of contributing, for reasons that are circumstantial but consistent:

• HS usually begins after puberty, when sex-hormone levels rise;
• it affects women more often than men in many populations;
• cycle-related changes are frequently reported;
• disease activity can change during pregnancy and around menopause;
• antiandrogen treatments appear to help some patients, though the supporting evidence is limited.

That is a reasonable case for hormones mattering. It is not an explanation of the mechanism, and researchers are clear about the difference.

Systematic reviews note that falling progesterone and oestrogen levels in the late luteal phase appear to coincide with flares in premenopausal women — but describe that association as speculative and awaiting experimental confirmation. The European S2k treatment guideline discusses hormonal and antiandrogen approaches for selected patients while noting that the role of sex hormones in HS remains debated. The American Academy of DermatologyDermatology: The medical specialty concerned with diagnosing and treating skin conditions. Acne Inversa is often managed by dermatologists, although surgery and other specialties may also be involved.DermatologyThe medical specialty concerned with diagnosing and treating skin conditions. Acne Inversa is often managed by dermatologists, although surgery and other specialties may also be involved.Read more in the glossary’s patient information says hormones may play a role, and that this might help explain premenstrual flaring — while describing HS causation overall as incompletely understood.

So a phrase that circulates widely online is worth retiring:

“My HS is hormonal.”

A more accurate version, and one that will serve you better in a consultation, is:

“My HS seems to follow a menstrual-cycle pattern.”

The second describes what you actually know.

Does a period-related flare mean my hormone levels are abnormal?

Not necessarily — and this is one of the most consequential misunderstandings in the topic.

Symptoms changing across the cycle does not demonstrate abnormal blood hormone concentrations. Systematic reviews of hormones in HS report that raised serum androgen levels have not been widely found in people with HS; measured hormone values usually sit within the normal range.

The hypothesis researchers favour instead is end-organ sensitivity: that the follicles themselves may respond unusually to hormone levels that are entirely ordinary. If that turns out to be right, then a normal blood test would be exactly what you would expect to see — and a normal result would not mean your experience was imaginary.

The practical consequences:

• Do not seek hormone testing solely because a website told you your HS is “hormonal.” Whether testing is useful depends on your broader history — irregular or absent periods, hirsutism, acne beyond your HS lesions, difficulty conceiving, or other symptoms suggesting an endocrine condition.
• Do not read a normal hormone panel as proof that your cycle pattern is not real. Those are different questions.

If you have both HS and features suggesting polycystic ovary syndromePolycystic Ovary Syndrome (PCOS): A hormonal condition involving irregular menstruation, excess androgens, ovarian cysts, and insulin resistance. Co-occurs with Acne Inversa at higher-than-expected rates, particularly in women whose HS flares with the menstrual cycle.Polycystic Ovary Syndrome (PCOS)A hormonal condition involving irregular menstruation, excess androgens, ovarian cysts, and insulin resistance. Co-occurs with Acne Inversa at higher-than-expected rates, particularly in women whose HS flares with the menstrual cycle.Read more in the glossary, that specific overlap is covered separately — PCOS occurs more often in people with HS than in the general population, and it is a recognised reason for coordinated assessment.

How can I tell whether there’s actually a pattern?

You do not need to document every detail of every day. You need to answer one question:

Does the same timing repeat?

That is a question about several cycles, not one. Given how unpredictable HS is anyway, a single flare landing before a single period tells you almost nothing — which is precisely why recall-based impressions are unreliable.

For three or four cycles, note:

What to note	Example
First day of bleeding	12 August
When HS symptoms changed	8 August
What changed	painful nodule, more tender than usual
Where	left groin
Effect on daily life	difficult to walk to work
When it settled	15 August

You are looking for repetition, not completeness. A cycle you forget to log does not ruin the record.

The difference this makes at an appointment is substantial. Compare:

“My hormones make my HS worse.”

with:

“Over the last four cycles, a painful lesion appeared two to five days before my period on three of them, and each time it settled a few days after bleeding started.”

The first invites a nod. The second is data a clinician can work with — and it is the kind of description that lets them judge whether the timing is meaningful for your management.

The site’s symptom tracker already records dates, symptoms, affected areas, daily impact, treatments and questions for your next appointment, so if you would rather not keep a separate notebook, the pattern can come out of entries you are already making. There is no separate cycle tracker here, and you do not need one — the first day of bleeding is one more date alongside the ones you are already logging.

Should I change my treatment before my period?

Not on the basis of this article.

Treatment decisions depend on your overall HS pattern, your current treatment, other health conditions, medications you take, your contraception needs and any pregnancy plans. None of that can be assessed from cycle timing.

Hormonal and antiandrogen approaches are recognised options for selected patients — the European guideline discusses them, and the AAD notes that hormonal therapy helps some women with HS. But the evidence is considerably weaker than online discussion suggests, and the newest data are a useful corrective.

In the 2026 survey, 20% of respondents had been prescribed metforminMetformin: A diabetes drug that also reduces insulin resistance. Modest evidence for Acne Inversa benefit, particularly in patients with metabolic syndrome or PCOS. Cheap and widely tolerated.MetforminA diabetes drug that also reduces insulin resistance. Modest evidence for Acne Inversa benefit, particularly in patients with metabolic syndrome or PCOS. Cheap and widely tolerated.Read more in the glossary, 9.8% spironolactoneSpironolactone: A potassium-sparing diuretic with anti-androgen activity. Used off-label in women with Acne Inversa, particularly those with flares around menstruation, hirsutism, or PCOS features. Cannot be used in pregnancy.SpironolactoneA potassium-sparing diuretic with anti-androgen activity. Used off-label in women with Acne Inversa, particularly those with flares around menstruation, hirsutism, or PCOS features. Cannot be used in pregnancy.Read more in the glossary, and 14.1% both. Among those who had tried metformin alone, 27% said it improved their HS. Among those who had tried spironolactone alone, 24% did. Those are self-reported figures from an uncontrolled survey, so they are not efficacy estimates — but they are a long way from the confident “hormonal HS responds to antiandrogens” framing that circulates in patient forums. The study’s own authors concluded that further research into antiandrogenic treatment for hormonally associated HS is needed.

The useful question to bring to an appointment is therefore not “should I start spironolactone?” but:

“My symptoms repeatedly worsen in the days before my period. Does that pattern change anything about how we should think about my treatment?”

Using hormonal contraception, or considering it? A cycle-related pattern is useful information to bring into that conversation, but different contraceptive methods may affect HS differently, the evidence is limited, and contraceptive safety and eligibility come first. → Birth control and HS

What to bring to your dermatologist

You do not need months of perfect records. Bring three things:

1. The pattern — when, relative to your period, the worsening tends to start and settle.
2. The impact — what it changes about pain, drainage, mobility, sleep, work or daily activities.
3. Your question — whether this repeatable timing has any implications for your management.

Questions worth asking:

• Does this look like a meaningful cycle-related pattern to you?
• Should we take this timing into account when judging whether my current treatment is working?
• Do any of my other symptoms make an endocrine or gynaecological assessment relevant?
• Are hormonal or antiandrogen approaches medically appropriate in my situation?
• Are there reasons they would not be suitable for me?
• Would it help if I kept documenting this over the coming months?

The point is not to arrive with a treatment already chosen. It is to arrive with better information than an impression.

What if my periods are irregular?

Irregular cycles make prospective pattern-spotting harder, because “seven days before my period” is not something you can identify in advance.

You can still record the same things: when bleeding starts, when symptoms change, and whether similar timing keeps recurring. Looking backwards over several cycles still shows a pattern if one is there.

If the irregularity itself is a concern, raise that separately with an appropriate healthcare professional. HS is associated at population level with several metabolic and endocrine conditions — but having HS, or having a period-related flare, does not diagnose any of them in an individual.

What about pregnancy and menopause?

Both are genuine HS topics, and neither is the same question as a monthly cycle pattern.

Disease activity can change during pregnancy and after menopause, and the findings vary between studies — the 2026 survey, for instance, found more than half of respondents reported worsening during pregnancy, which does not match the older assumption that HS reliably improves in pregnancy.

Those questions involve treatment safety, timing and planning decisions that deserve their own space, and this site keeps them separate rather than compressing them into a page about monthly patterns. If pregnancy, fertility or breastfeeding is your actual question, the dedicated hub is the better starting point. If your cycles have become irregular and you are wondering whether HS is expected to improve once periods stop altogether, HS, Perimenopause and Menopause covers that separately — and corrects a common assumption along the way.

Five things this article cannot tell you

• Whether your HS is “hormonal.”
• Whether you need hormone testing.
• Whether hormonal or antiandrogen treatment is suitable for you.
• What caused any individual flare.
• Whether your next period will bring one.

What it can do is help you judge whether the timing you have noticed is repeatable enough to deserve a proper clinical conversation.

The bottom line

Menstrual-cycle-related worsening of HS is a well-described patient experience, and the premenstrual week is the timing people report most often.

How many people it affects remains genuinely uncertain: published estimates run from roughly 43% to 96%, most come from self-selected online surveys, and the small amount of prospective research suggests that what changes may be how HS feels rather than how many lesions can be counted. The biologicalBiologic: A class of medications derived from living cells that target specific components of the inflammatory process. For Acne Inversa, biologics such as adalimumab and secukinumab are used when other treatments are insufficient.BiologicA class of medications derived from living cells that target specific components of the inflammatory process. For Acne Inversa, biologics such as adalimumab and secukinumab are used when other treatments are insufficient.Read more in the glossary explanation is incomplete, and normal hormone levels are the rule rather than the exception.

So if you keep noticing that your HS worsens around your period — neither dismiss it nor over-read it.

Document the timing across a few cycles. Describe the impact in concrete terms. Take the pattern to your dermatology appointment and ask what, if anything, it changes.

That is a considerably more useful place to arrive than “I think my HS is hormonal.”

If hormonal questions for you also touch on pregnancy or fertility, the HS, Pregnancy & Fertility guide covers that further. If they touch on perimenopause or menopause instead, HS, Perimenopause and Menopause is the dedicated guide.