Periods

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What are periods?

A period is the part of the menstrual cycle when a female passes blood from their vagina for several days. The length of a menstrual cycle varies from person to person but on average lasts around 28 days.  A period usually lasts between three and eight days.  Every month, one of the ovaries will release an egg; this is called ovulation.  During ovulation, hormonal changes prepare the uterus for a potential pregnancy.

If the egg is not fertilised, the lining of the uterus is shed through the vagina. This is your period. When the period is at its heaviest, the blood will be red. On lighter days, it may be pink, brown or black. Everyone's cycle is different and can be considered regular or irregular (in terms of length of time), light or heavy (in terms of flow), and painful or pain-free. 'Normal' is considered to cover a broad range, but you should talk to your GP if you see unusual changes in your individual circumstances.

Top period brands

NOTE: This article/page uses the terms ‘male/man/men’ and/or ‘female/woman/women’. Please note, this is in reference to the sex assigned at birth.

Information & support for your period

Starting your period can sometimes feel overwhelming and hard to deal with, but everyone's experience is different. If your symptoms are interfering with your daily life, talk to your GP to find support that is right for you.

Most women get their first period when they're between 10 and 15 years old. The average age is around 12 but there is no right age to start a period. Typically, you start your period about two years after your breasts start to develop. A sign that you may be starting your periods soon is an increase in vaginal discharge fluid (sort of like mucus, or thick egg whites) that you might see or feel on your underwear. This discharge usually starts six to 12 months before your first period.


Most women, unless there are medical reasons or hormonal interventions, will have a menstrual cycle of approximately 28 days, during which they will have a period, until the age of around 50, when menopause starts.

For most women, their cycle is 28 days, but it's common for periods to be more or less frequent than this, ranging from 21 to 40 days. These are the main stages of the menstrual cycle:


1. Menstruation - commonly known as a period. When you menstruate, your uterus lining sheds and flows out of your vagina.

2. The follicular phase - starts on the first day of your period and lasts for 13 to 14 days, ending in ovulation. The pituitary gland releases a hormone to stimulate the production of follicles on an ovary. Usually, only one follicle will mature into an egg. This causes the lining of the uterus to thicken further in preparation for potential pregnancy.

3. Ovulation - when a mature egg is released from an ovary and moves along a fallopian tube towards your uterus. This usually happens once each month, about two weeks before your next period. It is possible to get pregnant if you have unprotected sexual intercourse in the five days before ovulation and on the day of ovulation. Once the egg is released, it will survive for up to 24 hours.

4. The luteal phase - after ovulation, cells in the ovary release progesterone, and a small amount of oestrogen. This causes the lining of the uterus to thicken in preparation for pregnancy. If a fertilised egg implants in the lining of the uterus, progesterone levels continue to rise, which maintains the thickened lining of the uterus. If pregnancy does not occur, progesterone levels drop, the uterus lining sheds and the period begins.

The menstrual cycle is controlled by hormones. In each cycle, rising levels of the hormone oestrogen cause the ovary to develop and release an egg (ovulation). The womb lining also starts to thicken. In the second half of the cycle, the hormone progesterone helps the womb to prepare for implantation of a developing embryo. These changes in hormone levels over the monthly cycle can have an effect on your physical and mental wellbeing.

Period pain happens when the muscular wall of the womb tightens (contracts). Often, it's felt as painful muscle cramps in the tummy, which can spread to the back and thighs, and can come in intense spasms. You may also experience the feeling as a constant, dull ache. Some periods may be more painful than others, which you can find out more about in 'Period Pain Relief' under 'Ways to Support'.


You may also feel cramps during ovulation. You should speak to your GP if period pain is disrupting your life every month, if your symptoms progressively worsen or you experience cramps for the first time after the age of 26. You can also access period pain relief treatments, such as ibuprofen and heat patches. Alternatively, you can access a prescription-only medication via Boots Online Doctor.*

Polycystic ovary syndrome (PCOS) is a condition that affects how ovaries work. Your ovaries contain a large number of harmless follicles that are up to 8mm (approximately 0.3in) in size. The follicles are underdeveloped sacs in which eggs develop. In PCOS, these sacs are often unable to release an egg, which means ovulation does not take place.


The symptoms of PCOS can vary, but the most common symptoms are:

  • Irregular periods or no periods at all
  • Difficulty getting pregnant
  • Excessive hair growth usually on the face, chest, back or buttocks
  • Weight gain
  • Thinning hair
  • Hair loss from the head
  • Oily skin
  • Acne


If you think you may have PCOS, you should speak to your GP.

You may also choose to access a Circle Health Group private Consultant Gynaecologist who can assess your symptoms and, if appropriate, test, diagnose, and help treat or manage your condition.1

Endometriosis is a condition where tissue, similar to the lining of the womb, grows in other places, such as the ovaries and fallopian tubes. Endometriosis is a long-term condition that can affect women of any age. Some women are badly affected, while others might not have any noticeable symptoms.


Symptoms can vary, but most common are:

  • Pain in your pelvis or lower tummy (which is worse during your period)
  • Period pain that stops you doing your normal activities
  • Pain during or after sex
  • Pain when peeing or pooing during your period
  • Feeling sick
  • Constipation
  • Diarrhoea
  • Blood in your pee or poo during your period
  • Difficulty getting pregnant


Endometriosis can have a big impact on a female's life and may sometimes lead to depression. It's important to speak to your GP if you have symptoms of endometriosis.

You may also choose to access a Circle Health Group private Consultant Gynaecologist who can assess your symptoms and, if appropriate, test, diagnose, and help treat or manage your condition.1

There is a whole range of period products from tampons to period pants, pads to menstrual cups, and choosing which products are right for you and your period can be confusing. Everyone has a different preference, which can change from day to day, or dependant on your flow. It is about finding out which one is right for you from the following:


Tampons are small tubes, usually made of cotton and other materials, that you insert into your vagina to absorb the blood before it comes out of your body. Some tampons have an applicator to help you insert them into the vagina and some tampons are inserted using your fingers. Tampons are available in different sizes, which provide different levels of absorbency. Always read the instruction leaflet before inserting the tampon; you should not be able to feel it once it's inside you.


Pads (also known as sanitary pads/towels) are strips of padding that have a sticky side you attach to your pants to hold them in place. One side of the pad is made of an absorbent material that soaks up the blood. They come in many sizes and absorbencies, so you can change them depending on how heavy or light your period is. You may want to use a pad with a tampon at times when your flow is particularly heavy.


Menstrual cups are usually made from medical-grade silicone and are around two inches in size. The menstrual cup is usually folded in half and inserted into the vagina, where it collects the blood rather than absorbing it. Menstrual cups should be removed and washed before being used again. Because menstrual cups are reusable, they may reduce waste.


Period pants are designed to be worn during your period like everyday pants. Once worn, you should wash the pants in a washing mashine. There are different absorbencies depending on how heavy your period is. Period pants can be worn alone or alongside tampons and/or pads.

Period pain is normal and is usually felt as muscle cramps in the tummy, which can spread to the back and thighs. The pain may be constant or come in spasms. The first few days of your period are usually the most painful.  Period pain happens when the womb contracts or tightens, which temporarily cuts off the blood supply to your womb. The tissues in the womb release chemicals called prostaglandins, which help the womb contract more and increase the level of pain.


In most cases, period pan can be treated at home. Self-help measures, such as doing something you enjoy, taking a walk, eating your favourite food, having a warm bath or using a hot water bottle or heat patch on your stomach, may help. If self-help measures haven't helped, consider taking ibuprofen or aspirin**, if suitable for you, to help relieve the pain. If these medicines aren't suitable for you, or don't help with the pain, speak to your GP or consider Boots Online Doctor Period Pain Relief Service.*

The menstrual cycle is controlled by hormones and fluctuating levels of hormones may affect how you feel at different stages of the cycle. 


Premenstrual syndrome (PMS) is the name for a group of symptoms women can experience in the lead up to their period and may be linked to fluctuating hormone levels. Most women experience PMS at some point, but the frequency, range and severity of symptoms can vary. Symptoms may include:

  • Mood swings
  • Feeling upset, irritable or anxious
  • Headaches
  • Tiredness or trouble sleeping
  • Bloating or tummy pain
  • Breast tenderness
  • Spotty skin
  • Greasy hair
  • Changes in appetite or sex drive


During this time, talk to your loved ones about how you are feeling, try to get seven to eight hours sleep, eat a balanced diet and do some gentle exercise, such as yoga, and some women find that meditation can help. The NHS recommend you keep a diary of your symptoms for at least two to three cycles, so you can recognise if there are any patterns. If PMS is affecting you regularly, speak with your GP who will discuss options with you, which may include taking hormonal medicine, such as the combined contraceptive pill, to help with PMS symptoms.

You may experience bloating, low mood and low energy during your period. While these may mean that you don’t feel like exercising, physical activity may lessen these feelings and help you feel a little more energetic. You may not be able to manage your normal exercise routine, but to help you plan what type of exercise to do during your period, you could start tracking your menstrual cycle, mood and energy levels using a period diary.

A healthy diet, with plenty of fruit, vegetables, nuts, seeds, proteins and a variety of wholegrains, helps to support your general health. Ensuring you drink plenty of water and staying hydrated can reduce your risk of dehydration headaches.


Most women should be able to get all the iron they need by eating a varied and balanced diet. However, some women who have heavy periods and experience tiredness and low energy may benefit from an iron supplement. Iron contributes to the reduction of tiredness and fatigue. You should speak to your GP if iron supplements do not help to rule out a deficiency.

Period delay tablets contain a synthetic version of the hormone progesterone. Periods are triggered every month by a drop in progesterone levels. By keeping your hormone level high, you can delay your period for up to 17 days.


If you would like to be period-free for a big event or holiday, If treatment is appropriate for you, Boots Online Doctor Period Delay Service* can prescribe period delay tablets, with no need for an appointment with your GP

Access the treatment you need to help prevent period pain from cramping your style*

TABOO TALK PODCAST

3 women smiling as part of a poster for Episode 4 of the Taboo Talk podcast. The episode is named Periods

Season 1, Episode 4: A Bloody Good Chat About Periods


An informative & funny chat about periods & hormones with body confidence campaigner and ‘You’ve Gut This’ founder Lottie Drynan and ‘Obgyn Mum’ Dr Brooke Vandermolen.


This episode will be strictly periods & hormones-focused, & will cover such things as why Lottie started talking about her periods, why she thinks there’s still a stigma around discussing them, her personal experience with her cycle & how hormones affect her body & moods. We’ll then bring in Dr Vandermolen to get the science on hormones, periods, moods, pain & cramps. What is 'normal', what is 'worrying' and, in her experience, is the conversation becoming less taboo?

NHS healthcare information all about periods & how to manage them

Frequently asked questions

Toxic shock syndrome (TSS) is a very rare condition that can occur when bacteria get into the body and release harmful toxins. It is a medical emergency.


To avoid TSS, you should:

  • Wash your hands before and after changing your tampon or menstrual cup.
  • Wash your menstrual cup before each use.
  • Change your tampon or empty your menstrual cup regularly.
  • Always use a tampon with the lowest absorbency suitable for your period flow.
  • Change your tampon regularly, as often as directed on the pack (usually at least every four to eight hours).
  • Never have more than one tampon in your vagina at a time.
  • Consider alternating between tampon and a pad, panty liner, period pants or menstrual cup during your period.
  • When using a tampon at night, insert a fresh tampon before going to bed and remove it when you wake up.
  • Remove your tampon or period cup at the end of your period.
  • When using female barrier contraception, follow the manufacturer's instructions about how long you can leave it in. It is a good idea to avoid using tampons or female barrier contraception if you have had TSS before.


TSS is rare, but it can be life-threatening. You must call 111 (alternatively, contact your GP, or go to A&E, or call 999 for severe symptoms) if you're using tampons or a menstrual cup and you have:

  • A sudden high temperature
  • Flu-like symptoms
  • Sickness, or feeling sick
  • A skin rash
  • Diarrhoea
  • Dizziness or fainting
  • Difficulty breathing
  • Confusion


These symptoms can start very suddenly and you should take action immediately if you have a combination of these symptoms. If you are using a tampon or menstrual cup, remove it immediately and inform the doctor you see that you have been using tampons/a menstrual cup. 

Period odours aren't usually noticeable. Your period can have a slightly metallic smell due to the presence of iron in the blood and is not normally anything to worry about. Sometimes, there may be a slight odour (generally only noticeable by yourself) when using period pants or pads, but if you change them regularly and shower daily, it should minimise the odour. 


If you are concerned about the smell of your period, please speak to your GP to rule out any underlying causes.

Not always. A missed period can be caused by many things, such as:

  • Stress
  • Hormone fluctuations
  • New medications
  • Sudden weight loss or gain
  • Injury


However, if you’re worried and you are sexually active, you can take a pregnancy test up to six days before your missed period to check. If you have any questions, you may wish to talk to your Boots pharmacist or GP.


You should book an appointment to see your GP, or a midwife, as soon as you find out you are pregnant to ensure that you get the right access to antenatal care to support your pregnancy as soon as possible.

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The language surrounding sex, gender, and sexuality is always evolving, and different people have different views on the words that should be used. Therefore, we only mention sex, gender or sexuality when it's relevant, such as when providing our customers with the correct health information and treatment they need. We try to follow the NHS guidance for healthcare providers. You can find that here.

Page last reviewed by Boots Pharmacy team on 31/01/2023

Periods are a huge part of many women's lives and it's so important that we talk about them. It's vital that we boost our knowledge on periods and know where to turn when we're unsure of something - enter Boots! You can explore all the content we have compiled on menstruation, from period tips to PMS symptoms, right here. Discover more about the different options for dealing with your period, how to manage period problems and why you feel the way you do.