Guide
Over-the-counter vs prescription medicines — what is the difference
Prepared by the LekCheck team · Last reviewed: 2026-07-25 · How we create our content
Medicines are broadly divided into over-the-counter (sold without a prescription, OTC) and prescription (requiring a doctor's order). The division is not accidental — it reflects how safe a medicine is to use in self-treatment. Below we explain the differences and what they mean for you as a patient. This is general information, not advice on a specific medicine.
This guide was prepared by the LekCheck team and has not been reviewed by a doctor or pharmacist. This article is for general information only and is not medical advice, diagnosis, or treatment. Do not start, stop, or change any treatment without consulting a doctor or pharmacist.
What over-the-counter medicines are
Over-the-counter medicines (OTC) are meant for self-treatment of mild, common conditions — pain, fever, a cold, heartburn, mild itching. They have a well-established safety profile with correct use, but 'without a prescription' does not mean 'without risks' — the dose, duration and contraindications in the leaflet matter.
What prescription medicines are
Prescription medicines require a doctor's order because their use calls for a diagnosis, judging the dose, monitoring, or carries a greater risk of side effects and interactions. Examples are many antibiotics, medicines for chronic conditions and stronger painkillers. The prescription is a safety mechanism, not a formality.
Why some medicines require a prescription
The prescription requirement reflects a need for medical judgement — for example with a risk of misuse, serious side effects, interactions, or when it is important to confirm the diagnosis. That is why prescription medicines are not bought online without a prescription; a site that offers them without requiring one breaks the rules.
How to buy safely
For over-the-counter medicines, read the leaflet, follow the dose and ask a pharmacist if unsure, especially in pregnancy, with chronic conditions or when taking other medicines. For prescription medicines, turn to a doctor. Buy only from legal pharmacies — for online purchases, check for the EU common logo and the BDA (ИАЛ) register.
Frequently asked questions
Does 'without a prescription' mean 'safe for everyone'?
No. Over-the-counter medicines are safer for self-treatment with correct use, but they still have doses, contraindications and possible interactions. 'Without a prescription' means that, following the instructions, the risk is acceptable — not that the medicine is harmless for everyone in any use.
Can I buy a prescription medicine without a prescription?
Not legally. Prescription medicines require a doctor's order precisely because their use calls for medical judgement. A site or pharmacy that offers prescription medicines without a prescription breaks the rules and is not trustworthy.
Who decides whether a medicine is over-the-counter?
The classification (prescription or over-the-counter) is set by the regulatory authorities based on the safety profile, indications and risk of misuse. The same active substance can be over-the-counter at a lower dose and prescription at a higher one.
Do over-the-counter medicines interact with prescription ones?
Yes, it is possible. Over-the-counter products (e.g. some painkillers or supplements) can interact with prescription medicines. So it is important to tell the doctor and pharmacist what else you take, including supplements and herbal products.
How do I know if I need a prescription?
If the medicine is marked as prescription-only, or if the condition needs a diagnosis and medical monitoring, a prescription is needed. If unsure, ask a pharmacist — they can guide whether a complaint is suitable for self-treatment or it is better to see a doctor.