Answer the side-effect intent for lenacapavir without diagnosing; distinguish common from serious reactions and give safe next-step/reporting guidance.
Part of hiv & prep & arvs side effects.
Source
Clinical statements on this page are taken from the SAHPRA-approved patient information leaflet (approved 21 October 2025) and professional information (approved 21 October 2025) for this product: patient information leaflet, professional information. Retrieved 2026-09-03. Where this page and the approved leaflet differ, the leaflet is correct.
What is lenacapavir?
Which leaflet this comes from
There is no approved leaflet for Lenacapavir in SAHPRA’s public repository. The information below is from the approved leaflet for Lenacapavir 464 mg Solution for Injection Gilead, another South African product containing Lenacapavir sodium. Products with the same active ingredient can still differ in strength, formulation and approved uses, so check the leaflet in your own pack.
Lenacapavir contains the active ingredient Lenacapavir sodium.
- Active ingredient — Lenacapavir sodium
- Registration number — 60/20.2.8/0810
- Registration holder — Gilead Sciences South Africa (Pty) Ltd
It is approved for:
- S4 Lenacapavir Gilead contains the active substance lenacapavir
- It is a long acting antiretroviral medicine known as a capsid inhibitor
- Lenacapavir Gilead is used in combination with safer sex practices to prevent HIV-1 infection in adults and adolescents weighing at least 35 kg
- This is called pre-exposure prophylaxis (PrEP)
Common side effects of lenacapavir
Not everyone gets side effects. The effects below are those listed in the South African approved leaflet, grouped using the leaflet’s own frequency wording.
About these frequency terms
This leaflet groups effects on the very common/common/uncommon scale.
Very common side effects
- Reactions where Lenacapavir Gilead is injected Symptoms may include:
- a hardened mass or lump
- pain and discomfort
- inflammatory reaction such as redness, itching, and swelling
- open sore on the skin
Serious side effects and warning signs
This leaflet does not set out a separate list of serious side effects. The general warning signs below apply to any medicine.
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 lenacapavir from the SAHPRA-approved patient information leaflet or professional information, and cite what you actually used.
- Anything the approved information for lenacapavir 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
Factors that may affect side effects
The approved leaflet identifies the following cautions and factors.
Do not use it at all if
- If you are allergic to lenacapavir or any of the other ingredients of Lenacapavir Gilead (listed in section 6)
- If you do not know if you have HIV. You must get tested to make sure that you do not already have HIV. Lenacapavir Gilead can only prevent HIV if you don’t already have it
- If you are taking any of these medicines:
- carbamazepine, phenytoin, used to prevent seizures
- St. John’s wort (Hypericum perforatum), a herbal remedy used for depression and anxiety → Do not receive Lenacapavir Gilead and tell your doctor or nurse immediately if you think any of these apply to you
Use with care, and tell your doctor, if
- Take extra measures to prevent HIV while you are receiving Lenacapavir Gilead
- Get tested for HIV when your doctor or nurse tells you. You must get tested regularly to make sure that you stay HIV negative while receiving Lenacapavir Gilead
- Get tested for other sexually transmitted infections when your doctor or nurse tells you to
- Keep all your appointments to get your Lenacapavir Gilead injections on time. Talk to your doctor or nurse if you are thinking about stopping injections: stopping may increase your risk of getting HIV. If you do stop, or miss your scheduled Lenacapavir Gilead injections appointment, you may need to take other medicines or precautions to reduce your risk of getting HIV, and possibly developing viral resistance
- Tell your doctor or nurse straight away if you think you might have HIV (you may get a flu-like illness). They may want to do more tests to make sure you still do not have HIV. Talk to your doctor or nurse if you have any more questions about how to prevent getting HIV
- Lenacapavir Gilead injection is a long-acting medicine If you stop Lenacapavir Gilead injections, lenacapavir (the active substance in Lenacapavir Gilead) may remain in your body for a year or more after your last injection, but the amount of drug in your body may be too low to protect you from getting HIV. Children and adolescents Do not give this medicine to anyone weighing less than 35 kg because it has not been studied in these individuals
Pregnancy and breastfeeding
- If you are pregnant or breast-feeding, think you may be pregnant or are planning to have a baby, ask your doctor, nurse, pharmacist or other healthcare provider for advice before taking this medicine
- If you are breast-feeding, or thinking about breast-feeding, you should discuss it with your doctor or nurse
Interactions and medicines to check
The approved leaflet names these interactions.
- carbamazepine, phenytoin, used to prevent seizures
- St. John’s wort (Hypericum perforatum), a herbal remedy used for depression and anxiety → If you are taking any of these medicines, do not receive Lenacapavir Gilead injection and tell your doctor or nurse immediately. Talk to your doctor or nurse in particular if you are taking:
- medicines used to treat some bacterial infections, such as tuberculosis, containing:
- rifabutin, rifampicin or rifapentine
- anticonvulsants used to treat epilepsy and prevent seizures (fits), containing:
- oxcarbazepine or phenobarbital
- medicines used to treat migraine headache, containing:
- dihydroergotamine or ergotamine
- medicines used to treat impotence and pulmonary hypertension, containing:
- sildenafil or tadalafil
- medicine used to treat impotence, containing:
- vardenafil
- corticosteroids (also known as ‘steroids’) taken orally or given by injection used to treat allergies, inflammatory bowel diseases, and other various illnesses involving inflammations in your body, containing:
- dexamethasone or hydrocortisone/cortisone
- medicines used to lower cholesterol, containing:
- lovastatin or simvastatin
- antidysrhythmics used to treat heart problems, containing:
- digoxin
- medicines used to help you sleep, containing:
- midazolam or triazolam
- anticoagulants used to prevent and treat blood clots, containing:
- rivaroxaban, dabigatran or edoxaban → Tell your doctor or nurse if you are taking any of these medicines or if you start taking any of these medicines while receiving Lenacapavir Gilead. Do not stop any treatment without contacting your doctor or nurse. Lenacapavir Gilead is a long-acting medicine. If after talking to your doctor or nurse you decide to stop taking Lenacapavir Gilead, you should know low levels of lenacapavir can remain in your system for many months after your last injection. Some other medicines may be affected by the low levels of lenacapavir in your system if you take them within 9 months after your last Lenacapavir Gilead injection. You should check with your doctor or nurse if such medicines are safe for you to take after you stop Lenacapavir Gilead
Bring the actual products to the conversation
A pharmacist can check for interactions much faster from the packaging than from remembered names.
What to do if you experience side effects
If you think you are having a side effect, the response depends on how severe it is. Use the warning signs above first — if any of those apply, treat it as urgent.
If the symptom is severe or frightening
Get medical help immediately. Call 10177 for an ambulance, or 112 from a mobile phone, or go to the nearest emergency department. Take the product and its packaging with you if you can.
If the symptom is mild but bothering you
- Write down what the symptom is, when it started, and how it relates to when you take the product
- Check the leaflet that came with the product to see whether the symptom is listed
- Speak to your pharmacist — for many questions this is the fastest route to a useful answer
- Contact the prescriber if the symptom is affecting your daily life or is not settling
Do not stop a prescribed treatment on your own
Stopping some treatments suddenly causes its own problems, and the condition being treated may get worse. If you want to stop, ask a pharmacist or doctor how to do it safely — they can usually offer an alternative.
You can also report a suspected side effect in South Africa. Reporting does not replace getting medical advice, and you do not need to be certain the product was the cause.
When to seek urgent medical help
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 medicine 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-00356 · build rank 356 · 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.