Pick up a bottle of e-liquid and the label can look more technical than it needs to. There is a ratio, a strength in milligrams, a list of ingredients and often a warning triangle. None of it is complicated once someone talks you through it, and understanding what is actually in the bottle makes choosing your next one far easier.

This is the plain-English version. If you want the raw specification, our e-liquid ingredients facts sheet sets it out in full. Here we are more interested in what each ingredient does and why it matters to how your vape actually feels.

What is in a bottle of e-liquid

Compliant UK e-liquid is a short list. There are four things in it, and that is deliberate.

• Propylene glycol, or PG. A thin, clear liquid that carries flavour well and produces the slight catch at the back of the throat that many former smokers find familiar.
• Vegetable glycerine, or VG. Thicker and very slightly sweet. It produces the visible vapour and gives the draw a smoother, softer feel.
• Flavourings. Food-grade concentrates, the same broad family used in the food and drink industry, chosen and tested for inhalation.
• Nicotine. Optional. Plenty of e-liquid is sold with none at all, and many people step down to nicotine-free over time.

That is the whole recipe. There is no tobacco, nothing is burned, and there is no combustion, which is the central difference between vaping and smoking. Every bottle sold legally in the UK is notified to the MHRA before it reaches a shelf, and the ingredients must be declared.

PG and VG: the ratio that shapes the feel

The two base liquids are always blended, and the balance between them is written as a ratio. A 50/50 liquid is half PG and half VG. A 70/30 liquid is 70 per cent VG and 30 per cent PG, which is the more common way round for the higher-VG blends.

The practical effect is straightforward. More PG gives you sharper flavour, a firmer throat hit and a thinner liquid that wicks easily through the small coils in a pod kit. More VG gives you a softer, warmer draw and noticeably more vapour, but the liquid is thicker and needs a more open coil to keep up with it.

This is why the ratio is really a device question rather than a taste question. A compact pod kit or a mouth-to-lung device is happiest on a balanced 50/50. A sub-ohm kit built for a direct-to-lung draw wants a high-VG blend, usually 70/30 or thereabouts. Putting a thick 70/30 through a tight pod coil tends to starve it, and that dry, scorched taste is the result.

Nicotine strength, and the UK limits

Strength is printed in milligrams of nicotine per millilitre of liquid. A 10mg e-liquid holds ten milligrams in every millilitre. You will sometimes see the same figure expressed as a percentage, so 1 per cent is 10mg/ml and 2 per cent is 20mg/ml.

In the UK the maximum permitted strength is 20mg/ml, and any bottle containing nicotine is sold in 10ml or smaller. Both limits come from the Tobacco and Related Products Regulations and apply to every legitimate retailer. If you are ever offered something stronger or in a larger nicotine bottle, it is not compliant.

Larger bottles do exist, in 50ml and 100ml, but they are sold nicotine-free as shortfills. They are deliberately underfilled so you can add a separate 10ml nicotine shot yourself if you want nicotine, then shake the bottle to mix it through.

As a rough starting point, heavier previous smokers often settle around 20mg in a nicotine salt, moderate smokers around 10mg to 12mg, and lighter smokers around 6mg. Direct-to-lung vapers use far less, commonly 3mg to 6mg, because each inhale delivers considerably more vapour.

Freebase and nicotine salts

The same nicotine turns up in two forms and they behave differently. Freebase is the traditional preparation and has been in e-liquid the longest. It works perfectly well at lower strengths, but above roughly 12mg it starts to feel harsh in the throat for a lot of people.

Nicotine salts pair the nicotine with an acid, which lowers the pH and takes most of that harshness away. The result is that a 20mg salt can feel smoother than a 12mg freebase, while being absorbed a little more quickly. For someone making the switch from cigarettes and wanting the edge taken off a craving promptly, that combination is why salts have become the usual recommendation.

Reading a bottle in practice

Put together, a label reading "50/50, 10mg, 10ml" tells you this is a balanced blend suited to a pod or mouth-to-lung kit, at a middling nicotine strength, in the standard nicotine bottle size. A label reading "70/30, 0mg, 100ml shortfill" tells you it is a high-VG liquid for a sub-ohm kit, with no nicotine in it yet, and you will want a nic shot if you need one.

Our 10ml e-liquid range covers the first case and the wider e-liquid collection covers everything else. We are rated 4.8 out of 5 by over 4,800 UK customers, and if the label still is not making sense, our friendly advisers will happily read one with you rather than guess.

Frequently asked questions

What does PG/VG actually stand for?

Propylene glycol and vegetable glycerine. They are the two base liquids that carry the flavouring and nicotine. PG carries flavour and gives throat hit, VG gives smoothness and vapour.

Is there anything harmful in e-liquid?

Compliant UK e-liquid contains only PG, VG, food-grade flavourings and optionally nicotine, and must be notified to the MHRA before sale. Vaping is widely recognised as substantially less harmful than smoking, but it is not risk-free, and nicotine is addictive.

What is the strongest e-liquid I can buy in the UK?

20mg/ml, which is the same as 2 per cent. That is the legal maximum, and it is more than enough for almost everyone, particularly in nicotine salt form where it feels smooth.

Why is nicotine e-liquid only sold in 10ml bottles?

UK regulations cap nicotine-containing bottles at 10ml. Larger 50ml and 100ml bottles are sold nicotine-free as shortfills, with a separate 10ml nicotine shot added if you want one.

Does the PG/VG ratio change how much flavour I get?

Yes. Higher PG generally gives a sharper, more defined flavour, while higher VG rounds it off and produces more vapour. Matching the ratio to your device matters more than chasing one or the other.