Answer side-effect and tolerability questions around birth control injection, including expected changes, warning signs and safe escalation guidance.
Part of contraceptive injections side effects.
Sources
This page covers contraceptive injections — a group of products, not a single one. Each statement below is taken from the SAHPRA-approved patient information leaflet named beside it:
- SAYANA (medroxyprogesterone, approved 10/10/2025)
- NUR-ISTERATE (norethisterone enantate, approved 14/04/2022)
Retrieved 2026-09-03. Your own medicine’s leaflet is the one that applies to you, and where it differs from this page the leaflet is correct.
What is birth control injection?
Contraceptive injections covers several products registered in South Africa, not one. They work in a similar way, and their approved leaflets do not list identical side effects.
The medicines covered here, and the leaflet used for each:
- medroxyprogesterone — SAYANA, Pfizer Laboratories (Pty) Ltd (Suspension for injection)
- norethisterone enantate — NUR-ISTERATE, Bayer (Pty) Ltd (Solution for injection)
Check your own pack
Two medicines in the same group can differ in their approved uses, their cautions and their side effects. The leaflet inside your pack is the one that applies to you.
Who should take extra care
Cautions from each medicine’s approved leaflet.
Medroxyprogesterone (SAYANA)
Do not use it at all if:
- if you are hypersensitive (allergic) to medroxyprogesterone acetate or any of the other ingredients of SAYANA (listed in section 6)
- if you think you are pregnant, are pregnant or breastfeeding your baby
- if you have unexplained vaginal bleeding
- if you have severe liver disease
- if you have had or think you have cancer of the breast
- if you have inflammation in the wall of a vein often occurring in the legs
Use with care, and tell your doctor, if:
- if you have risk factors for osteoporosis (brittle bones) including
- chronic alcohol and/or tobacco use
- chronic use of drugs that can reduce bone mass, e.g., anticonvulsants or corticosteroids
- low body mass index (BMI) or eating disorder, e.g., anorexia nervosa or bulimia
- metabolic bone disease
- strong family history of osteoporosis
Norethisterone enantate (NUR-ISTERATE)
Do not use it at all if:
- If you are pregnant or think you might be pregnant
- If you are suffering from or have a history of a thromboembolic disorder in your veins. Thrombosis is the formation of a blood clot. This may occur for example in the blood vessels of the legs (deep vein thrombosis) and the lungs (pulmonary embolism). See also the section “NUR-ISTERATE and thrombosis”
- If you have or have had a severe arterial, including cardiovascular, disease such as heart attack, stroke or ischaemic heart disease (angina pectoris). See also the section “NUR-ISTERATE and thrombosis”
- If you suffer from increased blood pressure requiring treatment
- If you suffer or have suffered from a severe liver disease (as long as your liver function values have not returned to normal). Symptoms of a liver disease may be, for instance, yellowing of the skin and/or itching of the whole body
- If you have or have had a benign or malignant liver tumour
Use with care, and tell your doctor, if:
- you smoke
- you have diabetes
- you are overweight
- you have had venous thromboembolism or anyone in your immediate family has had a thrombosis (venous thromboembolism in a sibling or a parent at a relatively early age)
- anyone in your immediate family has had breast cancer
- you have high blood pressure
Common side effects of birth control injection
Each medicine in this group has its own approved leaflet, and the effects below are the ones that leaflet lists. They are shown separately rather than combined, because the leaflets do not agree on what to list or how to word it.
Medroxyprogesterone (SAYANA)
- increased weight
- anxiety
- depression
- difficulty sleeping
- irritability
- decrease in libido
- mood disorder
- headache
- dizziness
- feeling of having insects crawling on or under the skin
- excessive sleepiness
- migraine
The leaflet lists 24 more. Read the full leaflet.
Norethisterone enantate (NUR-ISTERATE)
- uterine/vaginal bleeding including spotting (light bleeding from the vagina similar to, but lighter than, a period)
- short lasting absence of monthly bleeding (amenorrhoea)
- increased weight
- dizziness
- headache
- nausea
- skin disorder such as rashes
- injection site reaction
- depressed mood
Bleeding, cycle and hormonal changes
Changes to bleeding and to the menstrual cycle are among the most commonly reported experiences with hormonal contraception, and they are one of the main reasons people stop a method. Knowing what pattern to expect with birth control injection makes it easier to tell an expected change from one worth checking.
Bleeding patterns can include lighter or shorter periods, irregular spotting between periods, or periods stopping altogether. Which of these is expected depends on the method, and on how long it has been used.
Evidence required before publish — source the following for birth control injection from the SAHPRA-approved patient information leaflet or professional information, and cite what you actually used.
- The bleeding pattern the approved information for birth control injection describes as expected
- How long the source says an irregular pattern typically continues before settling
- What the source says about periods stopping, and whether that is described as harmless
- Bleeding that the source says should prompt medical review
Bleeding that needs checking
Very heavy bleeding that soaks through protection hourly, bleeding with severe pain or dizziness, or bleeding after sex that is new for you should be looked at by a healthcare professional rather than waited out.
Serious side effects and warning signs
None of the leaflets reviewed set out a separate serious-effects list.
General warning signs that apply to any medicine
Call for emergency help now if any of these happen
- Difficulty breathing, wheezing, or tightness in the throat or chest
- Swelling of the face, lips, tongue or throat
- A widespread rash with blistering or peeling skin, or sores in the mouth, eyes or genitals
- Fainting, collapse, or a sudden severe drop in alertness
- Chest pain, or sudden weakness or numbness on one side of the body
- A fit (seizure), or confusion that comes on suddenly
In South Africa call 10177 for an ambulance, or 112 from a mobile phone. Go to your nearest emergency department if it is faster. Do not wait to see whether the symptom settles.
How long can side effects last?
How long a side effect lasts depends on the effect, the product, how long it has been used, and the person. Some effects ease within days as the body adjusts. Others continue for as long as the product is used. A few can persist after stopping, and some need review rather than waiting.
- Settling effects — mild effects that ease over the first days or weeks of use
- Ongoing effects — effects that continue while the product is being used and improve after stopping
- Persistent effects — effects that continue after stopping and need medical review
- Delayed effects — effects that appear after weeks or months rather than immediately
Which of these applies to a particular effect is a clinical question. If a side effect is not settling, is getting worse, or is affecting your daily life, that is worth a conversation with a pharmacist or doctor regardless of how long it has been going on.
Evidence required before publish — source the following for birth control injection from the SAHPRA-approved patient information leaflet or professional information, and cite what you actually used.
- Anything the approved information for birth control injection says about how long specific effects last
- Whether the source describes any effect as usually temporary, or as needing review if it persists
- Whether any effect is described as continuing after the product is stopped
What happens after stopping or changing the method?
What happens after stopping or changing birth control injection depends on the method. Some methods stop working as soon as they are removed or discontinued; others take longer to clear. This matters both for side effects and for whether you are still protected against pregnancy.
Contraceptive cover
If you are changing method, there is often a window where you need additional protection. Getting that timing right is the single most important part of switching — ask a pharmacist, nurse or doctor to confirm it for your specific change rather than working it out from a general description.
Side effects and cycle after stopping
Side effects linked to a hormonal method usually ease once the hormone clears, though the time this takes varies by method. Cycles may take several months to settle into their own pattern, and that pattern may not be the same as before the method was started.
Evidence required before publish — source the following for birth control injection from the SAHPRA-approved patient information leaflet or professional information, and cite what you actually used.
- What the approved information for birth control injection says about stopping or removal
- How long the source says it takes for the effect to wear off
- What the source says about return of fertility
- Any symptom the source says to expect after stopping, and any that needs review
When to contact a healthcare professional urgently
Some symptoms need medical attention straight away rather than an appointment in a few days. Do not wait to see whether they settle.
Call for emergency help now if any of these happen
- Difficulty breathing, wheezing, or tightness in the throat or chest
- Swelling of the face, lips, tongue or throat
- A widespread rash with blistering or peeling skin, or sores in the mouth, eyes or genitals
- Fainting, collapse, or a sudden severe drop in alertness
- Chest pain, or sudden weakness or numbness on one side of the body
- A fit (seizure), or confusion that comes on suddenly
In South Africa call 10177 for an ambulance, or 112 from a mobile phone. Go to your nearest emergency department if it is faster. Do not wait to see whether the symptom settles.
Get same-day medical advice if you have
- A high fever, or a rash together with feeling generally unwell
- Yellowing of the eyes or skin, or unusually dark urine
- Unusual bruising or bleeding that you cannot explain
- Severe or persistent vomiting or diarrhoea, especially if you cannot keep fluids down
- A sudden change in mood, or thoughts of harming yourself
- Any symptom that is rapidly getting worse
If you are having thoughts of harming yourself
Help is available in South Africa. The SADAG helpline is 0800 567 567, or you can go to your nearest emergency department. You do not have to wait until it feels like an emergency.
How to report a suspected side effect in South Africa
South Africa has an official system for reporting suspected side effects, run by the South African Health Products Regulatory Authority (SAHPRA). Reports from the public and from healthcare professionals are how safety signals get detected after a product is already in use.
Who can report
Anyone can report — you do not have to be a healthcare professional, and you do not need to prove that the product caused the problem. A suspicion is enough. Patients, caregivers and family members can all submit a report.
What to have ready
- The name of the product, its strength and form, and the batch number if you have it
- Why it was being used, and when it was started and stopped
- What the suspected reaction was, when it began, and how long it lasted
- Any other medicines, supplements or remedies being used at the same time
- Basic details about the person affected — age and sex are usually enough
How to report
SAHPRA accepts adverse reaction reports through its e-Services reporting system and through the Med Safety mobile app. Healthcare professionals can also report through the same routes. Current forms and access points are published on the SAHPRA site.
- SAHPRA Health Products Vigilance — the main vigilance and reporting hub
- SAHPRA e-Services — current adverse reaction reporting access
Reporting is not a substitute for medical care
If someone is unwell now, get medical help first and report afterwards. Urgent symptoms always take precedence over paperwork.
For a fuller walkthrough see how to report an adverse drug reaction.
Related pages
← Back to more contraception side effects.
Report a side effect
If you think you have had a side effect, you can report a suspected side effect in South Africa. Report a suspected side effect through the appropriate SAHPRA pathway where relevant.
Information only
This page gives general medicine-safety information for people in South Africa. It is not a diagnosis and not personalised medical advice. It cannot tell you whether a symptom you are having is caused by a particular product. Speak to a pharmacist or doctor about your own situation, and do not stop or change a prescribed treatment on the basis of a web page.
Editorial status: draft — not for publication
Brief SE-00366 · build rank 366 · Phase 2 · Tier 2. Every evidence slot on this page must be completed from the SAHPRA-approved source and the page signed off by a qualified clinical or pharmacy reviewer before it is published. Target length 1,300–2,000 words.