Menarche

Menarche (pronounced "men-AR-kee") is the medical term for your very first period. It's a normal part of puberty for people with a uterus and usually happens somewhere between the ages of 9 and 16. It means your body has started its menstrual cycle — the monthly process where the uterus prepares for a potential pregnancy and sheds its lining if one doesn't happen.

• Menarche is your first ever period.
• It usually happens between ages 9 and 16, with the average in the UK being around 12-13. [CHECK: current UK average]
• It's one of the later signs of puberty — breast development, pubic hair, and a growth spurt usually come first.
• First periods are often irregular. It can take a year or two before they settle into a pattern.
• Having your first period means it's physically possible to get pregnant, even if your cycle is irregular.

When it happens

Menarche doesn't arrive out of nowhere. It usually comes after other puberty changes have been going on for a while — breast development (often the first visible sign of puberty), pubic and underarm hair, a growth spurt, and an increase in vaginal discharge. Most people get their first period about 2-3 years after breast development starts.

The average age in the UK is around 12-13, but there's a wide range. Getting your period at 9 is normal. Getting it at 16 is also normal. If you haven't started your period by age 16, it's worth mentioning to a GP — not because something is necessarily wrong, but because they can check everything's developing as expected. [CHECK: current NHS guidance on when to seek advice for delayed menarche]

What the first period is like

First periods are often lighter and shorter than what you might expect. You might notice brown or reddish-brown spotting in your underwear, or a small amount of blood. It might not look like "proper" blood — more like a stain. Some people barely notice it.

You might get cramps, feel bloated, or have mood changes around your first period — or you might feel completely fine. Everyone's experience is different. First periods can also be a one-off for a while — you might have one and then not have another for several weeks or even months. This is normal in the early stages as your body figures out its rhythm.

Being prepared

If you haven't had your first period yet and you're in the age range where it could happen, it can help to keep a pad or liner in your school bag. If you're caught off guard, toilet paper works as a temporary solution, and school nurses, teachers, and friends can usually help. It's genuinely one of those things that feels like a bigger deal before it happens than after.

Products you can use include pads (stick to your underwear), tampons (inserted into the vagina), menstrual cups or discs (reusable, inserted into the vagina), and period underwear (absorbent pants). Pads are the most straightforward option to start with, but there's no rule about what you "should" use — try what you're comfortable with.

Things people get wrong

"You can't use a tampon for your first period." You can, if you want to. There's no medical reason to avoid tampons from the start. Some people prefer to start with pads because they're simpler, but it's your choice.

"Getting your period early means something is wrong." Puberty is starting earlier on average than it used to. A first period at 9 or 10, while on the younger end, is within the normal range. If puberty signs appear before age 8, a GP should check it out. [CHECK: current threshold for precocious puberty referral]

"Once you start your period, it'll be regular straight away." Usually not. It's very common for periods to be irregular — coming every few weeks, skipping months, varying in length — for the first couple of years.

Things people ask about menarche

Can I still do sports and swimming when I have my period?

Yes. You can do everything you normally do. For swimming, a tampon or menstrual cup works well. For other activities, whatever product you're comfortable with is fine.

Does getting your period mean I'm "a woman now"?

It means your body is going through puberty. It doesn't change who you are or mean you suddenly need to act differently. That "becoming a woman" framing is outdated and a bit weird — you're just you, going through a normal biological process.

What if I get my period at school and I'm not prepared?

Go to the school nurse or ask a teacher. Most schools have spare pads. If you're too embarrassed to ask, toilet paper folded into your underwear works temporarily. Almost everyone with periods has been caught out at some point — it's not as unusual or as dramatic as it feels.

Can I get pregnant once I've had my first period?

Yes, technically. Having a period means you're ovulating (or will be soon), which means pregnancy is possible. Your cycle may be irregular at first, which makes it harder to predict when you're fertile — but it doesn't mean you can't get pregnant.

Where to get help

• Your GP or school nurse — if your periods are very painful, very heavy, or haven't started by age 16.
• Brook — information and advice about periods and puberty for young people.
• NHS 111 — for advice if you're unsure whether something about your period needs medical attention.

Menarche is the medical word for your very first period. It's a normal part of puberty for girls and women.

It usually happens between the ages of 9 and 16. The average in the UK is around 12-13, but everyone is different. Getting it earlier or later than your friends is normal.

Your first period usually comes after other puberty changes have already started, like breasts developing, body hair growing, and getting taller.

The first period is often lighter and shorter than you might expect. It might just look like a brownish stain in your underwear. You might feel cramps or feel a bit moody, or you might feel completely normal.

After your first one, your periods might not come regularly for a while. They might skip months or come at different times. This is normal in the early stages. It can take a year or two for them to settle into a pattern.

It helps to keep a pad in your school bag in case it starts when you're not expecting it. If you're caught off guard, toilet paper works as a short-term fix, and school nurses usually have spare pads.

Once you've started your period, it's physically possible to get pregnant, even if your periods are irregular.

If your period hasn't started by age 16, it's worth seeing a doctor just to check everything is okay.