Abbreviation for "Over the counter", which means the medication or medical device can simply be purchased without needing a doctor's prescription for it. In Canada, ALL insulin and syringes are available as over the counter medications. In the US, the non analog insulins can be purchased without a prescription. In the UK, ALL insulins require a prescription, and in most if not all EU countries, ALL insulin also is Rx needed. Some countries also require a prescription for insulin syringes and/or pen needles. Categories and cover this in more depth.