What is e-liquid? Ingredients, PG/VG and the types you can buy
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- Four ingredients, nothing exotic. Propylene glycol, vegetable glycerine, food-grade flavouring and, optionally, nicotine.
- PG carries flavour and throat hit, VG carries vapour. The ratio printed on the bottle tells you which kit it is built for.
- Five formats. Ready-to-vape 10ml, nic salt 10ml, nicotine-free shortfills, nic shots and DIY concentrates.
- UK limits are strict. Nicotine-containing bottles cap at 10ml and 20mg/ml, and nicotine tanks and pods cap at 2ml. A 100ml bottle is legal only as a 0mg shortfill.
- Strength follows your old habit, not your ego. Twenty a day or more starts at 18mg freebase or 20mg salt; five to ten a day sits around 6mg freebase or 5mg to 10mg salt.
What e-liquid is made of
E-liquid, also called vape juice or e-juice, is the liquid a vape device heats. It sits in a tank or a pod, soaks into a cotton wick, and a coil warms it until it turns into an inhalable aerosol. Nothing is set alight and nothing burns.
The recipe is short and it is printed on the box. Every nicotine-containing liquid sold legally in the UK is notified to the Medicines and Healthcare products Regulatory Agency before it reaches a shelf, while 0mg liquids fall under general product safety law. A compliant bottle comes with an ingredient list, a batch number, child-resistant and tamper-evident packaging and a nicotine warning.
Propylene glycol
Thin, colourless, nearly odourless. Carries flavour compounds and produces the throat sensation. PG is also used in food and pharmaceutical products.
Vegetable glycerine
Thick, slightly sweet, plant derived. It is what makes visible vapour. VG is also used in food and pharmaceutical products.
Flavourings
Food-grade flavour concentrates. Fruit, menthol, dessert, drinks and tobacco-style profiles are the main groups.
Nicotine, optional
Measured in mg per ml. Common UK strengths are 3mg, 6mg, 10mg, 12mg, 18mg and 20mg. Plenty of liquid is sold at 0mg.
Occasionally you will see a trace of distilled water or ethanol in the list. Both are there for practical reasons, water to thin a very thick VG blend and ethanol to help certain flavour compounds dissolve, and both appear in small quantities.
What is not in the bottle
E-liquid is not burned and contains no tobacco leaf. That is a statement about what the liquid contains, not a comparison with anything else, and nicotine itself is addictive whichever product it comes in. If you want the regulatory detail behind what UK bottles may and may not contain, our summary of vape law and regulations in the UK goes through it.
PG and VG: what the ratio on the bottle means
PG and VG make up the bulk of any e-liquid, usually more than nine tenths of it, and the split between them is the most useful number on the label. It decides how thick the liquid is, how much vapour you see, how strong the throat hit feels and, critically, which coils it will wick into without burning.
| Ratio | Feels like | Vapour | Suits |
|---|---|---|---|
| High PG, 70/30 PG | Sharp throat hit, very forward flavour | Low | Older pen-style kits, tight mouth-to-lung |
| Balanced 50/50 | Moderate throat hit, clear flavour | Moderate | Pod kits and MTL tanks, coils of 0.6 ohm and above |
| High VG, 70/30 VG | Smooth, soft, rounder flavour | High | Sub-ohm tanks and box mods |
| Max VG, 80/20 and up | Almost no throat hit, thick and sweet | Very high | Low-resistance mesh, high wattage only |
The rule of thumb is simple. Small coil, thin liquid. Big coil, thick liquid. A 70/30 VG shortfill in a tight 1.0 ohm pod will not wick fast enough and you will taste a burnt wick within a few puffs, while a 50/50 in a big sub-ohm tank will leak straight out of the airflow. If you are not sure which camp you are in, read MTL versus DTL inhalation styles first, because the kit decides the liquid and not the other way round.
Freebase nicotine and nicotine salts
Nicotine appears in e-liquid in two chemical forms and they behave noticeably differently. Freebase is the traditional one. It is harsh at higher strengths, which is why freebase liquid is mostly sold between 3mg and 18mg, and it gives the pronounced throat kick that experienced vapers on bigger kits tend to like.
Nicotine salts are made by adding a mild acid, usually benzoic acid, which lowers the pH. The practical result is that 20mg of salt is far smoother to inhale than 20mg of freebase. That is why salts dominate the 10mg to 20mg end of the range and why almost every modern pod kit is sold with salts in mind. Our nic salt guide covers the range in more depth.
The five types you can buy
Everything on the e-liquid shelf falls into one of five formats. They exist because of the rules rather than because of taste, and once you know which one your kit wants, shopping gets a great deal faster.
| Format | Bottle | Nicotine | Mixing needed |
|---|---|---|---|
| Ready to vape 10ml | 10ml, usually 50/50 | 3mg to 18mg freebase | None |
| Nic salt 10ml | 10ml, 50/50 or 70/30 | 5mg, 10mg or 20mg salt | None |
| Shortfill | 50ml and up, VG heavy | 0mg as supplied | Add nic shots if you want nicotine |
| Nic shot | 10ml, unflavoured | 18mg freebase or 20mg salt | One shot per 50ml of shortfill |
| Concentrate | 10ml to 30ml flavour only | 0mg | Mix with your own PG, VG and shot |
Ready to vape 10ml. Open the cap and pour. Most of them are 50/50, which is exactly what a pod kit or a mouth-to-lung tank wants. Multipacks such as the Signature 10 x 10ml let you mix flavours and strengths in one go. Browse the full 10ml range.
Nic salts. Same 10ml bottle, different nicotine chemistry, and the format to reach for from 5mg up to the 20mg maximum. See the nic salts category.
Shortfills. A larger bottle of flavoured liquid at 0mg with headroom left at the top. The headroom is there for a nic shot if you want one, or you vape it as it comes at 0mg. Browse shortfills, and see shortfill versus 10ml for the direct comparison.
Nic shots. Ten millilitres of unflavoured nicotine in a PG/VG base, made to be poured into a shortfill. Match the ratio of the liquid you are dosing, so a 70VG shot like the Nic Nic 70VG nicotine shot goes into a 70/30 shortfill. The whole nic shot range is sold in 10ml bottles.
Concentrates. Pure flavour, no base and no nicotine, intended for people mixing their own from scratch. It is the cheapest route per millilitre and much the fiddliest. Have a look at DIY and concentrates if that appeals.
The UK rules that shape every bottle
Three numbers explain almost every format decision a UK brand makes.
10ml
maximum bottle size with nicotine in it
20mg
maximum nicotine strength per ml
2ml
maximum nicotine tank or pod capacity
A bottle bigger than 10ml is legal only if it contains no nicotine, which is precisely what a shortfill is. That is why there is no such thing as a 100ml nic salt: a 100ml bottle can only be sold at 0mg, and you add nicotine yourself at the point of use. Anyone offering you a large bottle of pre-nicotined liquid is not selling a compliant UK product.
Two further dates are worth having in your head. Single-use disposable vapes have been banned from sale in the UK since 1 June 2025, so refillable kits and rechargeable prefilled pod kits are the only legal grab-and-go options. And Vaping Products Duty starts on 1 October 2026 at £2.20 per 10ml plus VAT, and pre-duty stock can be sold until 31 March 2027. Our explainer on how much vape prices will go up runs the arithmetic.
Matching a strength to your smoking habit
Strength is the one variable people most often get wrong in both directions. Too low and you find yourself vaping constantly. Too high and it is unpleasant to inhale. The starting point is how much you used to smoke, and the second factor is what kit you are putting it in, because a high-powered device delivers far more nicotine per puff at the same mg.
| Habit | Freebase | Nic salt |
|---|---|---|
| Social, under 5 a day | 3mg | 5mg |
| Light, 5 to 10 a day | 6mg | 5mg to 10mg |
| Moderate, 10 to 15 a day | 10mg to 12mg | 10mg |
| Heavy, 15 to 20 a day | 12mg to 18mg | 10mg to 20mg |
| Very heavy, 20 plus a day | 18mg | 20mg |
Two footnotes to that table. On a sub-ohm, direct-to-lung kit the usual strength is 3mg, occasionally 6mg, in a high-VG shortfill with a shot, and 18mg or 20mg should never go in a sub-ohm kit. If you want no nicotine at all, a shortfill with no shot added is 0mg as supplied. Treat the table as a starting line rather than a prescription, and give any new strength a couple of days before you judge it. There is a fuller walkthrough in how much nicotine should I vape. If you are choosing your very first bottle and want help narrowing down a flavour rather than a strength, start with our fruit e-liquid buying guide, which is the post that covers picking a first liquid properly.
One last practical note. E-liquid keeps well but it does not keep forever. Stored upright, sealed, cool and out of sunlight, an unopened bottle is generally good for a year or two, and the main change over time is colour and flavour rather than anything else. See e-liquid shelf life and storage tips before you buy in bulk.
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Quick answers
Is vape juice the same thing as e-liquid?
Yes. Vape juice, e-juice and e-liquid are three names for the same product. Some brands use one term on the bottle and another on the box.
Does all e-liquid contain nicotine?
No. Shortfills and concentrates are sold at 0mg as standard, and plenty of 10ml bottles are available nicotine free. Nicotine is an optional ingredient.
What is the batch number on the box for?
It ties the bottle to one production run. If a brand ever withdraws a batch, or you want to check that a nicotine product matches its MHRA notification, that number is what identifies it, so keep the box until the bottle is finished.
What PG/VG ratio should I start with?
50/50, unless you already own a sub-ohm tank or box mod. It works in almost every pod kit and mouth-to-lung tank, carries flavour well and wicks into small coils without trouble.
Why does my tank only hold 2ml?
UK rules cap a nicotine-containing tank or pod at 2ml, so every compliant kit is built to that size.
Is PG or VG responsible for a scratchy throat?
PG carries most of the throat sensation, and nicotine strength adds to it. A small number of people find high PG blends drying and do better on a VG-heavier liquid.
