Heavy periods: what counts as heavy and the treatments that work

SASian Anderson, Writer and editor, MyGLP. Sources checked 5 November 2026.

The NICE definition puts your life first

The NICE guideline on heavy menstrual bleeding, NG88, defines it as excessive menstrual blood loss which interferes with a woman's physical, social, emotional and/or material quality of life. There is no millilitre target to hit. If you plan your week around your period, buy pads in bulk for the car and avoid pale clothes, your period is heavy in the eyes of the guideline your GP works to.

The Women's Health Strategy for England notes most women will menstruate for nearly 40 years and names heavy menstrual bleeding as a condition which affects women at work. In the evidence behind the strategy, women said they were often told heavy and painful periods were normal. Common is a different thing from normal, and you do not have to put up with it.

Signs your periods are heavy

The NHS heavy periods page gives practical signs. You may have heavy periods if you:

• Change a pad or tampon every 1 to 2 hours, or empty a menstrual cup more often than the maker recommends.
• Need two products at once, such as a pad and a tampon.
• Bleed for more than 7 days.
• Pass clots larger than about 2.5cm, the size of a 10p coin.
• Bleed through to clothes or bedding.
• Avoid exercise or other activities, or take time off work.
• Often feel tired or short of breath.

What causes heavy periods

For many women no cause is found, and treatment still works. The NHS lists these causes:

What happens at the GP

NG88 sets out the assessment. Your GP will ask about your bleeding, pain, bleeding between periods or after sex, and the effect on your life. Depending on your answers they may examine your tummy and pelvis.

• A full blood count for every woman with heavy periods, done alongside any treatment, not instead of it (NG88, recommendation 1.2.6).
• A pelvic ultrasound if the womb can be felt through the tummy, a mass is suspected, or the examination is unclear.
• A transvaginal ultrasound in preference to other scans if you have significant period pain or a bulky, tender womb, which can suggest adenomyosis.
• An outpatient hysteroscopy, a camera passed into the womb, if your history suggests fibroids inside the cavity, polyps, or a problem with the lining, such as persistent bleeding between periods.

In July 2026 NICE removed the recommendation on ferritin testing from the NG88 laboratory tests section. Iron stores still matter. Our iron guide covers ferritin, iron-rich food and how to take tablets, so we will not repeat it here.

Treatments, in the order NICE suggests

NG88 recommends considering the levonorgestrel intrauterine system (LNG-IUS), the hormonal coil, as the first treatment for women with no identified cause, fibroids under 3cm which do not distort the womb, or suspected or diagnosed adenomyosis. If you decline the coil or it is not suitable, NICE lists the alternatives below.

Tranexamic acid is the option many women have not heard of. It reduces bleeding without hormones and you take it only on the heavy days. The NHS tranexamic acid page says you usually take it 2 to 3 times a day for a few days, and some forms can be bought from a pharmacy, though most need a prescription. A pharmacist can tell you whether it suits you.

The NHS treatment page adds that your GP will usually refer you to a specialist if first treatments do not work. Ask what the next step is before you leave the room, so you know when to come back.

Heavy periods on a weight loss medicine

Your cycle often shifts as weight comes off, and a heavier period or two as ovulation restarts is common. Our guide to periods on weight loss injections covers what to expect. Two points are specific to heavy periods.

• If the combined pill is your heavy period treatment, the MHRA warned in June 2025 that Mounjaro may reduce how well oral contraceptives work in people who are overweight, and advised adding a non-oral method. The hormonal coil, patch and ring are non-oral methods.
• Eating less on a jab lowers the iron coming in while heavy periods take it out. Tiredness and breathlessness are reasons to ask for the full blood count NICE recommends.

Before your appointment

1. Track two periods: days of bleeding, how often you change products, clots, and any flooding at night.
2. Note days off work, school or plans because of bleeding.
3. List any tiredness, breathlessness or dizziness.
4. Bring a list of medicines, including any weight loss medicine and blood thinners.
5. Say what matters to you: contraception, a future pregnancy, or avoiding hormones. The right option depends on it.

Sources

1. Heavy menstrual bleeding: assessment and management (NG88) (NICE)
2. Heavy menstrual bleeding (NG88), full recommendations (NICE)
3. Heavy periods (NHS)
4. Heavy periods: treatment (NHS)
5. How and when to take tranexamic acid (NHS)
6. Adenomyosis (NHS)
7. Women's Health Strategy for England (2022) (Department of Health and Social Care)
8. Weight loss injections: contraception warning for women, June 2025 (MHRA, via the Department of Health Northern Ireland)