VG and PG explained: how the ratio changes flavour and throat hit

Every e-liquid bottle is built on a base of two ingredients before a drop of flavouring or nicotine goes anywhere near it: vegetable glycerine (VG) and propylene glycol (PG). The ratio between them, printed on the label as something like 50/50 or 70/30, has a bigger effect on how a vape feels than most people expect. If you've ever wondered why the same flavour tastes different in two bottles, or why one pod kit feels harsh and another feels smooth, the VG/PG ratio is usually the answer.

What VG and PG actually are

Vegetable glycerine is a thick, faintly sweet liquid derived from plant oils. It's already used widely in food, cosmetics and medicine. In e-liquid, VG is the ingredient mainly responsible for vapour production: the denser and more visible the cloud, the more VG is usually doing the work.

Propylene glycol is thinner and almost odourless, also long-used in food, asthma inhalers and stage fog machines. In e-liquid, PG is the better carrier for flavouring compounds, and it's the ingredient mostly responsible for what's known as throat hit, the slight peppery catch at the back of the throat that many ex-smokers find gives a more cigarette-like sensation.

Typical ratios on UK shelves

UK e-liquid is commonly sold in a handful of standard ratios, and most bottles state theirs clearly on the front label.

• 50/50 VG/PG: an even split, the standard base for most nicotine salt bottles and entry-level pod kits.
• 60/40: a slightly thicker, VG-leaning option still compatible with most pod and MTL devices.
• 70/30: a common shortfill ratio for sub-ohm tanks, favouring vapour production over sharp flavour and throat hit.
• Max VG (80% or higher): used almost exclusively in high-wattage sub-ohm setups built for large clouds.

How the ratio changes flavour

Because PG carries flavour compounds more efficiently through a coil, higher-PG liquids generally taste crisper and closer to the bottle's description, particularly with sharper notes like citrus or menthol. As the VG proportion increases, flavour tends to come across softer and slightly sweeter, since VG itself has a mild natural sweetness and mutes some of the sharper top notes. Neither is "better" in absolute terms; it's a genuine trade-off between clarity of flavour and density of vapour. We go through the flavour families themselves, including which tend to suit which ratio, in our guide to how e-liquid flavour works.

Throat hit, explained properly

Throat hit is largely down to PG, though nicotine strength plays a role too, since nicotine itself adds a degree of throat sensation independent of the base ratio. A 50/50 liquid at a moderate nicotine strength will generally feel firmer on the throat than a max-VG liquid at the same strength. This is one reason nicotine salt liquids, which are typically formulated to feel smoother at higher nicotine strengths, are so often sold in 50/50 rather than high-VG bases: the ratio is chosen to balance out the strength.

Matching ratio to device

VG/PG ratio isn't just a taste preference, it also needs to suit the hardware. Higher-VG liquid is thicker and takes longer to soak into a wicking material, which is fine for a sub-ohm tank designed with that in mind, but can cause dry hits or leaking in a low-wattage MTL pod built around thinner liquid.

• MTL (mouth-to-lung) pod kits and starter devices: usually paired with 50/50 or 60/40 liquid, which wicks well through the narrow airflow and higher-resistance coils these devices use.
• DTL (direct-to-lung) sub-ohm kits: built around low-resistance coils and open airflow, these are designed for 70/30 or max-VG liquid, which wicks well at higher wattage and produces the dense clouds these devices are made for.

50/50 versus 70/30 versus max VG

Shortfills and nicotine shots

Many UK shoppers meet VG/PG ratios for the first time through shortfills: nicotine-free bottles, commonly 50ml or 100ml, sold with extra headroom so one or more 10ml nicotine shots can be added afterwards. A shortfill's base ratio is fixed by the manufacturer before you buy it, typically something like 70/30, and adding a nicotine shot (usually mixed at 50/50 or 60/40 itself) shifts the final ratio slightly toward PG. It's a small shift on a large bottle, so it rarely changes the feel dramatically, but it's worth knowing if a shortfill tastes a touch sharper once a nic shot has gone in than it did straight from the bottle.

Some more experienced vapers mix their own ratios from scratch using separate VG and PG bases, flavour concentrates and nicotine shots, which allows fine control over the final blend. That's a more involved hobby in its own right, with its own safe-handling and labelling considerations, and it's outside the scope of this guide; most readers will get on perfectly well buying pre-mixed liquid at a stated ratio.

A couple of practical notes

A small number of people report mild sensitivity to PG, sometimes showing as a dry throat, mild cough or slight skin irritation from residue. If that sounds familiar, a higher-VG or max-VG liquid is usually worth trying instead. On the hardware side, thicker high-VG liquid can gunk up a low-wattage MTL coil more quickly than the coil is designed for, so it's worth matching liquid to device rather than assuming any ratio works in any tank. Coils also generally need priming (letting new wicking material fully soak through) before use, and that takes a little longer with a thicker, high-VG liquid than with a thinner 50/50 mix.

The VG/PG ratio is one of the pieces of information UK-compliant e-liquid has to display clearly on the bottle. For a full walk through everything else that has to appear on a compliant label, see how to read an e-liquid label in the UK.