No period yet: when a first period is late

The NHS advises a check if your first period hasn’t come by 15, or by 13 if there are no other signs of puberty. You can also ask for advice sooner if you’re worried about your growth or development.

If your friends already have periods, it can be hard to keep their experiences separate from your own questions. At the appointment, ask about the changes you’ve noticed and any checks you might need. Make time for your own questions about what happens next.

Puberty begins before your first period

Breast growth and hair under the arms or around the genitals (pubic hair) are signs of puberty. A first period comes later. The NHS says periods usually start about 2 years after breasts begin to grow. This is a common pattern. It can’t tell you when your own periods will start.

Primary amenorrhoea is the medical name for when a first period hasn’t started. It’s different from secondary amenorrhoea, which means periods stopping after they’ve started. A check looks at puberty as well as periods. That’s because the cause can involve hormone signals, the ovaries or how the reproductive organs formed.

Why you may see different ages online

NHS advice on periods uses 15 without a first period, or 13 without other signs of puberty. Its more recently reviewed page on missed periods also advises a GP check if periods haven’t started by 15.

In the US, ASRM recommends tests if there’s no first period by 15 even though other signs of puberty are there, or no breast growth by 13. MedlinePlus says puberty is late if there’s no breast growth by 13 or no periods by 16. But it also says to contact a clinician if puberty hasn’t started by 13 or isn’t moving on.

These sources use different definitions and wording. You can still ask about a worry before those ages. Tell the GP or children’s doctor your age and which changes you’ve noticed. You don’t need to work out the right label before the appointment.

The possible explanations

Late puberty can run in families. Sometimes the body simply starts developing later, and no treatment is needed. A clinician may ask when close family members started puberty, as well as asking about your own health and growth.

Other possible reasons include not getting enough food, hard training, long-term conditions such as coeliac disease or diabetes, and problems with hormone signals from the ovaries or brain. Past cancer treatment and some genetic conditions can also affect puberty. A clinician can look into these. The timing of a first period alone can’t tell you the cause.

What an appointment may involve

Expect questions about your family history, eating, exercise and health, then an examination. Tests may include hormone blood tests, an X-ray of your hand or wrist to check how your bones are developing, or an ultrasound or MRI scan if needed. Your clinician will choose tests to check your development and look for a cause.

You can ask what each part of an examination involves before it starts. If a parent or carer is coming with you, decide what you’d like them to help explain. They can bring questions about growth or family history and still leave room for your own questions.

Getting support while the cause is checked

If you keep getting pain low in your tummy or pelvis without a first period, contact your GP (UK), or your doctor or a children’s doctor (US or elsewhere). Don’t wait for the ages above. Go to A&E now (UK), or an emergency department (US or elsewhere), if you can’t pee or have severe tummy pain.

Treatment depends on what is found. It may mean treating another condition, help with food, or hormones to help puberty move on. Feeling upset or distressed is also a good reason to ask about treatment and support. Your GP or specialist can explain the options. Don’t try to start your periods with hormones or supplements on your own.

Book with a GP in the UK, a doctor or children’s doctor in the US, or your local doctor or clinic elsewhere, following the advice above. Before you leave, ask when your development will be checked again, whether you’ll see a specialist and who to contact if you have more worries.