Information  /  What’s in a vape?

A legal nicotine vape sold in Great Britain usually contains a small number of main ingredients, but the device, liquid and aerosol are not all the same thing. Knowing the basics makes it easier to understand labels, spot unusual products and avoid myths.

Last reviewed: 25th September 2026

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Some e-liquids are nicotine-free. When the liquid is heated it forms an aerosol that is inhaled. It is often called “vapour”, but it is not simply water vapour.

No. Vapes create an aerosol from heated e-liquid. The aerosol can contain nicotine, flavouring chemicals and other substances formed or released during heating.

That does not make vaping equivalent to smoking. Legal vapes expose users to significantly fewer harmful substances than cigarettes, which burn tobacco and produce tar, carbon monoxide and thousands of chemicals. Vaping is still not risk-free.

Under current Great Britain product rules, nicotine-containing vapes must be notified to the MHRA before sale. Rules include a maximum nicotine strength of 20 mg/ml, a maximum tank or pod capacity of 2 ml, and a maximum 10 ml nicotine refill container. Certain ingredients, including caffeine and taurine, are prohibited.

These rules help distinguish legal consumer products from products that do not meet UK requirements.

An illegal vape may exceed nicotine limits, contain prohibited ingredients or fail to appear on the MHRA notification list. Products sold as THC, CBD or cannabis vapes sit outside ordinary nicotine-vape assumptions and may contain unexpected substances, including synthetic cannabinoids.

You do not need to dismantle a device or investigate its contents yourself. Look at the packaging, nicotine strength, product name and where it came from. If a young person becomes unwell after using an unknown vape, deal with their health first and tell medical staff what you know.