Unifen 400 is ibuprofen 400 mg — an anti-inflammatory painkiller for headache, period pain, dental pain, back and muscular pain, sprains and fever. The 400 in the name is the strength, not part of the brand, and it happens to be the dose where ibuprofen’s benefit levels off while its risks keep climbing.

What is Unifen 400?

Unifen is a South African brand of ibuprofen, listed on the Medicine Price Registry as a Schedule 3 tablet. Unifen 400 denotes the 400 mg strength; a 200 mg version also exists.

Ibuprofen is a non-steroidal anti-inflammatory (NSAID). It blocks the COX enzymes that produce prostaglandins — the chemicals responsible for pain, swelling and fever where tissue is injured or inflamed. It acts at the site of the problem rather than dulling perception centrally, which is why it suits inflammatory pain far better than paracetamol.

Why 400 mg specifically is the number worth knowing.

400 mg is the standard effective adult dose. It is the strength at which ibuprofen’s anti-inflammatory effect is reliable, and it is what most trials of ibuprofen for pain have used.

Above 400 mg per dose, pain relief barely improves. The dose-response curve for analgesia flattens out — 600 mg gives very little more relief than 400 mg for most acute pain. But the stomach, kidney and cardiovascular risks keep rising. That asymmetry is the single most useful thing to understand about ibuprofen dosing, and it is why taking extra tablets when 400 mg has not worked is a poor trade rather than a reasonable escalation.

If 400 mg is not enough, the answer is usually a different approach — adding paracetamol, which works by a separate mechanism, or reconsidering what is causing the pain — not more ibuprofen.

Ibuprofen is sold under many names — Nurofen, Inza, Brufen, Adco-Ibuprofen, Ibuflam, Unifen. Same active ingredient; the price difference between brands can be considerable and the medicine is identical.

Among the common anti-inflammatories, ibuprofen is the best tolerated — lower cardiovascular risk than diclofenac, and a large evidence base. At low doses occasionally it is genuinely mild. At 400 mg three times daily for weeks it is not, and the risks scale with dose and duration in a way most people underestimate.

What is Unifen 400 commonly used for?

Headache, including tension headache and migraine.
Period pain, where an anti-inflammatory is genuinely more effective than paracetamol, since prostaglandins drive the cramping directly.
Dental pain and toothache, as short-term relief while awaiting treatment.
Back, neck and muscular pain.
Sprains, strains and sports injuries, where swelling matters as well as pain.
Arthritis pain, including osteoarthritis flares.
Fever in adults.
Cold and flu aches — the symptoms, not the infection.
Pain after minor surgery or a procedure.

Two things that change outcomes.

For period pain, start it before the pain is established — at the first sign, or the day before if your cycle is predictable. Anti-inflammatories prevent prostaglandin production far more effectively than they reverse pain already underway.

Paracetamol and ibuprofen together work better than either alone, because they act by different mechanisms. For dental and post-operative pain the evidence for the combination is genuinely strong, and it often removes the need for anything stronger.

It is for short-term use. Pain lasting beyond a few days needs a cause found, and regular painkiller use for headache can itself cause medication-overuse headache, where the treatment sustains the problem.

How Unifen 400 fits into this medicine category

Group	Examples	Notes
NSAIDs	Ibuprofen (Unifen 400), diclofenac, naproxen	Pain, fever, inflammation; stomach, kidney, heart cautions
Oxicams	Meloxicam, lornoxicam	Longer acting; once or twice daily
COX-2 selective	Celecoxib, etoricoxib	Gentler on the stomach; cardiovascular caution
Simple analgesics	Paracetamol	Pain and fever; no anti-inflammatory effect; safest
NSAID + paracetamol	Mypaid Forte	Two mechanisms in one tablet
Corticosteroids	Prednisone	Powerful anti-inflammatory, in courses
Topical NSAIDs	Ibuprofen or diclofenac gel	Local effect, far less absorbed

For a localised muscle or joint problem, a gel is often the better choice — much lower whole-body exposure and correspondingly lower risk. This is genuinely underused.

See the pain, inflammation and musculoskeletal medicines hub.

What to check before using Unifen 400

Do not take another anti-inflammatory alongside it — no diclofenac, naproxen, mefenamic acid, or aspirin at painkilling doses. Check cold and flu products, which frequently contain ibuprofen.

Speak to a pharmacist or doctor before using it if you:

Have or have had a stomach ulcer, gastritis, or bleeding in the gut.
Have kidney disease, liver disease, or heart failure.
Have high blood pressure or established heart disease.
Have asthma. Anti-inflammatories trigger severe attacks in a minority of asthmatics — if you have never taken ibuprofen and have asthma, ask first.
Are over 65, where stomach and kidney risks rise substantially.
Have inflammatory bowel disease.
Take warfarin or another blood thinner, low-dose aspirin for the heart, steroids, an SSRI antidepressant, an ACE inhibitor, ARB or diuretic, lithium or methotrexate.
Are pregnant. NSAIDs are avoided, particularly after 20 weeks; paracetamol is preferred.
Are breastfeeding, or planning pregnancy — NSAIDs can interfere with ovulation.
Are giving it to a child. Children are dosed by weight using a paediatric suspension, not adult tablets.

Practical points:

Take it with or just after food.
Follow the pack instructions for how much and how often, and the daily maximum.
Do not exceed 400 mg per dose expecting more relief. You get the risks without the benefit.
Use it for a few days, not indefinitely.
Drink enough fluid, particularly in hot weather or during a vomiting or diarrhoea illness. Dehydration plus an anti-inflammatory is genuinely hard on the kidneys.

Possible cautions and when to ask a pharmacist or doctor

Common effects: indigestion, heartburn, nausea and abdominal discomfort, much reduced by taking it with food. Headache and dizziness also occur.

Get emergency help for:

Vomiting blood, or material like coffee grounds.
Black, tarry stools.
Severe abdominal pain.
Chest pain, sudden breathlessness, or signs of a stroke — face drooping, arm weakness, difficulty speaking.
Swelling of the face, lips or tongue, or difficulty breathing.
A widespread blistering or peeling rash.
Severe wheezing after taking it.

Seek prompt advice for:

Persistent indigestion or stomach pain. Do not simply take an antacid and carry on — ibuprofen can cause an ulcer that bleeds without warning symptoms.
Worsening asthma.
Reduced urine output, swollen ankles, or unusual tiredness.
A rash or itching.
Bruising or bleeding more easily.
Ringing in the ears.

See a doctor if pain is not controlled, if you need it for more than a few days, if you take it most days, or if pain comes with fever, weight loss, numbness, weakness or loss of bladder or bowel control. Those need assessment, not a stronger painkiller.

For a child, seek advice for a fever that will not settle, reduced feeding or wet nappies, drowsiness, or a rash that does not fade under pressure.

Related medicine guides

Frequently asked questions

What is Unifen 400 used for? Headache, period pain, dental pain, back and muscular pain, sprains, arthritis and fever. It contains ibuprofen 400 mg.

Does the 400 mean something? Yes — it is the strength in milligrams, not part of the brand name. A 200 mg version also exists.

Is Unifen the same as Nurofen or Brufen? All contain ibuprofen. Different manufacturers, same active ingredient — and often a considerable price difference.

Can I take more if 400 mg does not work? Not usefully. Above 400 mg per dose, pain relief barely improves while stomach, kidney and cardiovascular risks keep rising. Adding paracetamol works better.

Can I take it with paracetamol? Yes, they work by different mechanisms and the combination is more effective than either alone. Do not combine it with another anti-inflammatory.

Is it better than paracetamol for period pain? Usually yes — and it works best started at the first sign rather than once cramping is established.

Can I take it with asthma? Ask first. Anti-inflammatories trigger severe attacks in a minority of people with asthma.

Can I take it in pregnancy? Ask your doctor. NSAIDs are generally avoided, particularly after 20 weeks.

Can I give it to my child? Not adult tablets. Use a paediatric ibuprofen suspension dosed by weight.

What Is Unifen 400 Used For?