How Long Does It Take Paracetamol To Work?

Scott McDougallMPharmDirector & Registered Manager

Reviewed on 22 Jul 2022

Paracetamol is a pain reliever and a fever reducer. It’s used to treat migraines, muscle aches, stomach pain, toothaches, period pain, arthritis, and other types of mild to moderate pain. It’s also used to reduce fever. Paracetamol can take up to one hour to work, but relief usually begins within thirty minutes.

Paracetamol is one of the most widely used pain relievers and fever reducers. Its exact mechanism of action is still unknown to science, but it’s thought to work by blocking pain signals that are sent to the brain. Unlike ibuprofen, paracetamol is ineffective when treating inflammation, but it’s also particularly effective at lowering fevers — this is achieved through altering the body’s temperature-regulating centre in the brain.

Paracetamol is available in many forms, including tablets, capsules, liquids, and suppositories. It’s also available in combination with other ingredients such as caffeine or codeine. If you’re suffering from mild to moderate pain, you may be wondering exactly how long paracetamol may take to kick in, or you may be questioning whether this is the best treatment for you. If that’s the case, read on below.

What’s paracetamol used for?

For acute pain (a headache, for example), just one dose of paracetamol should provide relief. If the pain returns later, additional doses may be taken. In situations where the pain is persistent or more intense, a combination of paracetamol and a stronger painkiller such as codeine may be required. However, paracetamol won’t offer relief from pain caused by inflammation, such as osteoarthritis. In these instances, ibuprofen is a much better option.

How long does it take paracetamol to work in adults?

Paracetamol can take up to one hour to work, but relief usually begins within thirty minutes. The rate at which the drug takes effect is influenced by various factors, including:

Your age
Your weight
When you last ate a full meal
How the medication was taken — it’s thought that effervescent, water-soluble paracetamol may take effect faster than traditional capsules or pills.

How and when should you take paracetamol?

Paracetamol can be taken with or without food. The usual dose for adults is one or two 500mg tablets up to 4 times in 24 hours. Always leave at least 4 hours between doses. Overdosing on paracetamol can cause serious side effects. Do not be tempted to increase the dose or to take a double dose if your pain is very bad. Instead, seek further medical attention.

Remember: An adult can take a maximum of 4 doses (up to eight 500mg tablets in total) within 24 hours. Always wait at least 4 hours between doses.

The dosage limit for children can vary:

Age	Dosage	Frequency
6 to 8 years	250mg	Max 4 times in 24 hours
8 to 10 years	375mg	Max 4 times in 24 hours
10 to 12 years	500mg	Max 4 times in 24 hours
12 to 16 years	750mg	Max 4 times in 24 hours

What’s the difference between paracetamol and ibuprofen?

Paracetamol and ibuprofen are both painkillers, but they work differently. Ibuprofen, aspirin, and other NSAIDs (non-steroidal anti-inflammatory drugs) work mostly at the location of pain, whereas paracetamol acts centrally by preventing the pain signals from reaching the brain.

Frequently asked questions

How long does it take for paracetamol to work for period pain?

If you’re suffering from period cramps, it’s completely understandable that you’re looking for fast relief. While paracetamol can get to work within 30 minutes to an hour, it’s also worth considering ibuprofen as an alternative. This is because ibuprofen treats pain while also reducing swelling in the body.

Can you take paracetamol on an empty stomach?

Paracetamol can be taken with or without food, but taking it on an empty stomach may help to reduce the time it takes for the treatment to take effect.

Can you take paracetamol when pregnant?

Paracetamol can be taken for pain relief during pregnancy, but pregnant women should always seek medical advice before taking paracetamol or other medicines.