Quick answer: Yes — paracetamol (acetaminophen/Calpol) is safe for babies from 2 months old who weigh at least 4kg (8.8lbs). Dose by weight, not age, and always follow the packaging instructions. Ibuprofen is safe from 3 months and at least 5kg.
Dosing correctly: weight, not age
This is the most important rule. Paracetamol is dosed by weight — the same ‘age’ can cover a huge range of weights, and using an age-based dose for a small baby can mean under-dosing, while using it for a large baby can mean over-dosing. The standard paracetamol dose for children is 15mg per kg of body weight, given every 4–6 hours, with a maximum of 4 doses in 24 hours. Children’s paracetamol suspensions (120mg/5ml is the standard UK concentration for infants; 160mg/5ml is common in the US) come with a dosing syringe marked in weight — use this, not a kitchen spoon. Example: a 6kg baby needs 6 × 15 = 90mg of paracetamol per dose, which is 3.75ml of 120mg/5ml suspension.
When to use paracetamol
Paracetamol is appropriate for: fever above 100.4°F (38°C) / 100.4°F that is causing the baby discomfort; pain (post-vaccination soreness, teething pain, pain from illness); and after the MenB vaccine in the UK where paracetamol is proactively recommended regardless of whether fever has developed. Important: treating fever in a baby under 3 months does not replace seeking medical attention — any fever in a baby under 3 months is a medical emergency and paracetamol management while travelling to hospital is appropriate, but does not substitute for emergency evaluation.
Paracetamol vs. ibuprofen: when to use which
Paracetamol and ibuprofen both reduce fever and pain through different mechanisms and can be used together or alternated for better effect. Paracetamol: from 2 months; acts on the central nervous system; no anti-inflammatory effect; gentler on the stomach; duration 4–6 hours. Ibuprofen: from 3 months and 5kg; anti-inflammatory in addition to fever/pain reduction; more effective for conditions involving inflammation (ear infections, teething); duration 6–8 hours. Do not use ibuprofen for chickenpox (associated with severe skin infections) or if baby is dehydrated or has kidney problems. Alternating the two (giving one, then the other 3 hours later) is sometimes recommended by healthcare providers for sustained high fever — this should be done on medical advice, not routinely.
What to avoid
Never give adult paracetamol (500mg tablets) to children — the concentration is entirely wrong. Never give aspirin to children under 16 years (risk of Reye’s syndrome). Never exceed the stated dose or give more frequently than every 4 hours. Don’t give paracetamol to prevent fever before vaccination (except the MenB vaccine where it’s specifically recommended) — evidence suggests this may slightly reduce the vaccine’s immune response.
Frequently Asked Questions
Can I give paracetamol to a 2-month-old after their vaccinations?
Yes — from 2 months and 4kg+, infant paracetamol suspension is safe. In the UK, paracetamol is specifically recommended after the MenB vaccine (given at 8, 16 weeks, and 1 year) regardless of whether fever develops — follow the specific guidance given at the vaccination appointment.
My baby spat out the paracetamol — do I give more?
If you’re confident they spat it all out immediately, you can repeat the dose. If they’ve swallowed some but not all, wait until the next scheduled dose time — it’s safer to underdose than to risk overdose. You can mix paracetamol into a small amount of breast milk or formula to improve acceptance.
Is there a sugar-free version of infant paracetamol?
Yes — sugar-free versions of infant paracetamol suspension are widely available and are recommended particularly if baby is having paracetamol regularly, to protect developing teeth.
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