Ivermectin is an antiparasitic medicine used in specific cases to treat infections caused by certain parasites. In the UK, ivermectin tablets may be used under medical guidance for conditions such as scabies and some intestinal or tropical parasitic infections. Like all medicines, ivermectin tablets can cause side effects, and the risk may depend on the condition being treated, the dose, body weight, medical history, and other medicines a person is taking.
Many people search online for ivermectin tablets, ivermectin UK, ivermectin 3mg tablets, ivermectin 6mg tablets, or ivermectin 12mg tablets when looking for treatment information. However, ivermectin should not be treated like a general over-the-counter supplement. It should only be used when it is clinically suitable and supplied through a responsible route with appropriate medical advice.
This guide explains the possible side effects of ivermectin tablets in clear UK language, including common symptoms, rare serious reactions, overdose warning signs, and when to speak to a GP, pharmacist, or NHS 111.
What are ivermectin tablets used for?
Ivermectin tablets are used to treat certain parasitic infections. In the UK, ivermectin may be considered for conditions such as human sarcoptic scabies, particularly when clinically appropriate. It may also be used for certain intestinal or tropical parasitic infections under professional supervision.
You can read more general treatment information through ivermectin UK resources, or check available ivermectin tablets through a responsible, prescription-aware route. Different strengths may be listed, including ivermectin 3mg tablets, ivermectin 6mg tablets, and ivermectin 12mg tablets, but the correct dose should always depend on body weight, diagnosis, and professional advice.
Taking a higher strength or repeating the dose without medical guidance can increase the chance of side effects.
Common side effects of ivermectin tablets
Not everyone gets side effects from ivermectin, and many effects are mild and temporary. However, some people may feel unwell after taking it. Possible common or expected side effects can include nausea, vomiting, diarrhoea, stomach discomfort, dizziness, tiredness, sleepiness, headache, weakness, itching, or a skin rash.
Some side effects may happen because of the medicine itself. Others may happen because the parasites are dying and the body reacts to that process. This can be especially relevant in some parasitic infections where itching, rash, swelling, or flu-like symptoms may temporarily worsen.
1. Nausea, vomiting, or stomach upset
Some people feel sick after taking ivermectin tablets. Others may experience vomiting, diarrhoea, constipation, or abdominal discomfort. These symptoms are usually short-lived, but they should not be ignored if they become severe or persistent.
If vomiting happens soon after taking the medicine, speak to a pharmacist or doctor before taking any extra dose. Do not repeat the dose yourself unless a healthcare professional tells you to.
2. Dizziness or sleepiness
Ivermectin may cause dizziness, vertigo, drowsiness, or a sleepy feeling in some people. This can affect driving, work, or using tools and machinery.
If you feel dizzy, sleepy, shaky, or less alert after taking ivermectin, avoid driving and avoid activities that require full concentration until you feel normal again. Alcohol may make dizziness or drowsiness worse, so it is sensible to avoid alcohol while taking ivermectin unless a clinician confirms it is safe for your situation.
3. Headache, weakness, or tiredness
Headache, weakness, low energy, or general tiredness may occur. These symptoms may be mild, but they can still affect daily activities. Rest, hydration, and avoiding alcohol may help, but medical advice is needed if symptoms are severe, unusual, or do not settle.
4. Itching or rash
Itching and rash can happen after ivermectin. In scabies, itching may also continue for some time even after treatment because the skin remains irritated while it heals. This does not always mean the medicine has failed.
However, a worsening rash, painful rash, blistering, peeling skin, mouth ulcers, eye irritation, or swelling of the face or lips should be treated as more serious. These signs need urgent medical advice because rare severe skin reactions can occur with medicines, including ivermectin.
5. Temporary worsening of scabies symptoms
People using ivermectin tablets for scabies may notice that itching does not disappear immediately. Itching can continue for several weeks after treatment as the skin recovers. This can be frustrating, but it does not always mean a second dose is needed.
A second dose should only be taken when advised by a healthcare professional. It may be considered in certain cases, such as new lesions, confirmed ongoing infestation, or crusted scabies, but this decision should be made clinically.
Good hygiene measures are also important. Bedding, towels, and clothing may need washing according to public health advice, and close contacts may need assessment or treatment to reduce the risk of reinfection.
Serious side effects to watch for
Serious side effects are rare, but they can happen. Seek urgent medical advice if you experience any of the following after taking ivermectin tablets:
Severe skin rash, blistering, peeling skin, or sores in the mouth.
Difficulty breathing, swelling of the face, lips, tongue, or throat.
Severe dizziness, fainting, confusion, or unusual behaviour.
Seizures, difficulty walking, severe weakness, or loss of coordination.
Yellowing of the skin or eyes, dark urine, severe abdominal pain, or signs of liver problems.
Severe eye pain, vision changes, red eyes, or unusual eye swelling.
Reduced consciousness, extreme sleepiness, or being difficult to wake.
These symptoms are not normal and should be checked quickly.
Ivermectin and severe skin reactions
Very rare but serious skin reactions have been reported with ivermectin. These can include severe conditions where the skin blisters or peels. Warning signs may include a widespread rash, painful skin, fever, mouth ulcers, eye soreness, or peeling skin.
If these symptoms appear, stop taking further doses and seek urgent medical help. Do not restart ivermectin after a severe skin reaction unless a specialist clearly advises it.
Ivermectin and neurological side effects
Neurological side effects are uncommon, but they are important. Some people may experience tremor, dizziness, sleepiness, confusion, difficulty standing or walking, or changes in alertness. Very rare severe effects can include reduced consciousness or coma, especially in certain high-risk situations.
People who have lived in or travelled from areas where Loa loa infection is common should tell their doctor before using ivermectin. In people with a high parasite burden, certain serious reactions may be more likely.
Ivermectin and liver-related side effects
Liver-related side effects are uncommon, but raised liver enzymes, liver dysfunction, or hepatitis have been reported. Speak to a doctor if you develop yellow skin or eyes, dark urine, pale stools, severe fatigue, persistent nausea, or pain in the upper right side of the abdomen.
People with existing liver problems should get medical advice before using ivermectin tablets.
Who may be at higher risk of side effects?
Some people may need extra caution before taking ivermectin tablets. This includes people who are pregnant or breastfeeding, children under the advised weight range, older adults with multiple health conditions, people with liver disease, people with a weakened immune system, and anyone taking other medicines.
People who are taking sedatives, medicines affecting the nervous system, or multiple prescription medicines should speak to a healthcare professional before using ivermectin. A pharmacist or doctor can check whether ivermectin is suitable and whether any interactions or safety concerns apply.
Ivermectin overdose: what to do
Taking too much ivermectin can be dangerous. Possible overdose symptoms may include nausea, vomiting, diarrhoea, abdominal pain, dizziness, rash, swelling, headache, breathing difficulty, seizures, poor coordination, unusual tingling, or severe drowsiness.
If overdose is suspected, do not wait for symptoms to become worse. In the UK, call NHS 111 for urgent advice or 999 if the person is severely unwell, unconscious, having breathing problems, or having a seizure.
Ivermectin and COVID-19
Ivermectin should not be used as a self-treatment for COVID-19. It is not a general antiviral medicine for home use, and using it for the wrong reason can delay proper diagnosis and treatment. If you have COVID-19 symptoms or are concerned about infection, follow current NHS guidance and speak to a healthcare professional where needed.
Buying ivermectin tablets online in the UK
People often search for buy ivermectin online UK, ivermectin tablets UK, or ivermectin for sale when they are looking for convenient treatment. Online access can be useful, but it must be safe and regulated.
Be careful with websites that offer prescription medicines without proper checks, do not show clear pharmacy details, make unrealistic claims, or encourage bulk buying without medical assessment. Unregulated online sources may supply unsuitable, poor-quality, fake, or unsafe medicines.
A responsible route should include appropriate medical screening, clear product information, pharmacist or clinician oversight, and advice on when not to use the medicine.
When should you speak to a doctor?
Speak to a GP, pharmacist, or NHS 111 if side effects are severe, continue longer than expected, or affect your daily life. You should also get advice if itching becomes worse after treatment, new skin lesions appear, you think scabies has returned, or you are unsure whether a second dose is needed.
Seek urgent help if you have breathing difficulty, severe allergic symptoms, severe rash, blistering, confusion, seizures, difficulty walking, vision changes, or signs of overdose.
Final thoughts
Ivermectin tablets can be useful for certain parasitic infections when used correctly, but they are not risk-free. Common side effects may include stomach upset, dizziness, headache, tiredness, itching, or rash. Rare but serious risks can include severe skin reactions, neurological effects, liver problems, allergic reactions, and overdose symptoms.
For UK patients, the safest approach is to use ivermectin only when clinically appropriate and with professional guidance. Do not increase the dose yourself, do not repeat treatment without advice, and do not rely on unregulated online sellers. If symptoms continue or side effects worry you, speak to a healthcare professional before taking further tablets.
Suggested sources to add at the end
NICE CKS: Ivermectin prescribing information for scabies
BNF/NICE: Ivermectin medicine information
eMC: Ivermectin 3 mg Tablet Patient Information Leaflet
eMC: Ivermectin 3 mg Tablet Summary of Product Characteristics
GPhC: Buying medicines safely online
MHRA: Yellow Card reporting for suspected medicine side effects
