Codeine is one of the most widely used opioid painkillers in the UK. It is available at low strength as a Pharmacy (P) medicine in combination with paracetamol or ibuprofen, and at higher strengths on prescription only. The 30 mg strength — usually combined with 500 mg paracetamol as co-codamol 30/500 — is the most commonly searched-for prescription codeine product in the UK.
This page is for adults who want to understand what codeine is, when 30 mg might be appropriate, what the safer alternatives are, and how a regulated UK pharmacy can supply it. It is not a recommendation to take codeine — any decision to prescribe is made by a UK-registered clinician.
What is codeine?
Codeine is a weak-to-moderate opioid analgesic. In the body it is converted by an enzyme (CYP2D6) into morphine, which is what produces most of the pain-relieving effect. Because people metabolise codeine at very different rates, two people taking the same dose can get quite different levels of pain relief — and quite different side effects.
In the UK codeine is available as:
- Codeine phosphate tablets (15 mg, 30 mg, 60 mg) — POM.
- Co-codamol 8/500 (8 mg codeine + 500 mg paracetamol) — Pharmacy (P) medicine, sold under the supervision of a pharmacist.
- Co-codamol 15/500 and 30/500 — Prescription Only.
- Nurofen Plus and similar codeine + ibuprofen products — Pharmacy (P) only.
- Codeine linctus — used for dry cough; reclassified to POM by the MHRA in 2024 because of misuse and dependence risk.
What is codeine used for?
- Short-term mild-to-moderate acute pain not adequately relieved by paracetamol or NSAIDs alone.
- Acute musculoskeletal pain, dental pain, post-injury pain or post-surgical pain, where simpler analgesics have not worked.
- As a step-up on the WHO analgesic ladder — usually after paracetamol and an NSAID such as ibuprofen or naproxen.
Codeine is generally not recommended as long-term pain relief. NICE guidance on chronic primary pain explicitly advises against starting opioids for chronic pain because of poor evidence of long-term benefit and clear evidence of harm.
Codeine 30 mg in context
30 mg is the highest standard single oral dose of codeine in the UK. It is usually given as co-codamol 30/500 — one or two tablets up to four times daily, with no more than 8 tablets in 24 hours.
- It provides more pain relief than 8/500 or 15/500 in many patients.
- It also produces more constipation, drowsiness and nausea.
- The total paracetamol dose still must not exceed 4 g in 24 hours from any source — including cold and flu products.
- It is intended for short courses, with review and a clear stopping plan.
Who may be prescribed codeine 30 mg?
A UK prescriber will usually consider codeine 30/500 for adults who:
- Have moderate acute pain not relieved by paracetamol and/or an NSAID.
- Do not have a history of opioid or other substance dependence.
- Do not have severe asthma, COPD or other significant respiratory problems.
- Do not have severe liver impairment, paralytic ileus or recent head injury.
- Are not pregnant or breastfeeding (codeine is contraindicated in breastfeeding due to risk of opioid toxicity in the infant).
- Are aged 18 or over (codeine is contraindicated in under-12s and not recommended in 12–18s after tonsillectomy/adenoidectomy).
How is codeine prescribed in the UK?
Codeine is unusual in that it spans three legal categories in the UK:
- Pharmacy (P) — low-dose combination products such as co-codamol 8/500 can be supplied by a pharmacist after a safety check, for a maximum of 3 days of use.
- Prescription Only (POM) — codeine phosphate 15/30/60 mg and co-codamol 15/500 and 30/500 require a prescription from a UK-registered prescriber.
- Schedule 5 controlled drug — codeine is classed as a controlled drug under the Misuse of Drugs Regulations 2001, with record-keeping requirements for pharmacies.
Since 2009 all over-the-counter codeine products in the UK have carried a mandatory addiction warning on the pack and in the patient information leaflet, following MHRA action on opioid dependence.
Safer alternatives — to try first
- Paracetamol 1 g four times daily at the maximum effective dose, for an adequate trial period.
- NSAIDs such as ibuprofen or naproxen — provided you have no contraindications. See our safer pain relief guide.
- Topical NSAIDs for localised musculoskeletal pain.
- Non-medicine approaches — graded exercise, physiotherapy, heat/ice, sleep, pacing. See our pain self-management guide.
- For ongoing pain affecting mood and sleep, talking therapies can help reduce the impact of pain.
Risks, side effects and safety
Common side effects
- Constipation (very common — drink plenty of fluids, eat fibre).
- Drowsiness, dizziness, dry mouth.
- Nausea, especially when first starting.
- Headache.
Serious risks
- Dependence and addiction — even short courses can lead to tolerance and withdrawal symptoms; longer use significantly increases the risk of opioid use disorder.
- Breathing suppression, especially when combined with alcohol, benzodiazepines or other sedatives.
- Paracetamol overdose — combining co-codamol with other paracetamol-containing products (Lemsip, Solpadeine, etc.) can cause severe liver damage.
- Ultra-rapid metaboliser status — a small number of people convert codeine to morphine very rapidly, which can cause toxic effects even at standard doses.
Do not use codeine if you
- Have severe asthma, COPD, or any other significant breathing problem.
- Have a paralytic ileus or recent head injury.
- Are breastfeeding.
- Have a history of opioid or other substance dependence.
- Are under 18 in certain situations (see BNF / NHS guidance).
Driving: codeine is covered by UK drug-driving law. If you have been prescribed codeine and your driving is not impaired, you have a statutory medical defence — but it is an offence to drive while impaired.
Legal and regulatory status in the UK
- Schedule 5 controlled drug under the Misuse of Drugs Regulations 2001.
- POM at 15 mg and above; P in low-dose combination products.
- OTC codeine products are limited by MHRA to 3 days of use and must carry an addiction warning.
- Pharmacies supplying codeine in the UK must be UK-registered and comply with controlled-drug record-keeping rules.
How a RestWell Pharmacy consultation works
- You complete a confidential online pain assessment covering the cause of your pain, how long you have had it, what you have already tried, your medical history and any medication you take.
- You provide photo ID and confirm your GP details. With your consent we may notify your GP — particularly important for opioids.
- A UK-registered prescriber reviews your case. They may approve a short course of codeine, propose a safer non-opioid option, or decline if treatment is not appropriate.
- If approved, the medicine is dispensed by our registered pharmacy and dispatched in plain, tracked packaging.
- You receive clear written safety information and access to our pharmacist for follow-up questions.
Frequently asked questions
Is codeine 30 mg strong?
It's a moderate-strength opioid dose. 30 mg is the highest standard single dose of codeine in the UK and is usually combined with paracetamol as co-codamol 30/500. It is more potent than 8/500 or 15/500 but also more likely to cause constipation, drowsiness and dependence with continued use.
Can I buy codeine online without a prescription in the UK?
No. Higher-strength codeine (15 mg and above) is Prescription Only. Low-dose combinations such as co-codamol 8/500 are Pharmacy medicines and can be supplied without a prescription only after a pharmacist safety check, for a maximum of 3 days of use. Any UK website selling stronger codeine without a prescription is operating illegally.
Is codeine addictive?
Yes. Codeine is an opioid and all opioids carry a risk of dependence and addiction, even when used as directed. The risk increases with dose, duration, and combination with other sedatives.
Can I take co-codamol with paracetamol?
No — co-codamol already contains paracetamol. Taking additional paracetamol risks exceeding the maximum daily dose (4 g in 24 hours) and causing serious liver damage.
Will my GP be told?
For opioid prescriptions we strongly recommend GP notification, in line with CQC guidance. You can decline, but this may affect the prescriber's decision to prescribe.