Imagine tipping a bottle of e-liquid onto a plate and watching it separate. What you would see is not a mystery cocktail of chemicals. It is, for the most part, just four things: two clear base liquids, a dash of flavouring, and, in most bottles, nicotine. That short list is the whole answer to what's in a vape, and understanding it changes how you choose every bottle you buy.
This guide pours out each ingredient one by one, busts the myths about what is not in the bottle, decodes the ratio on the label, and shows you how to read an e-liquid label like a pro. Along the way, you will see exactly why one juice hits your throat hard while another fills the room with clouds. One note before we start: vaping is a harm reduction option for adult smokers who want to switch away from cigarettes. It is not for non-smokers, and it is never for under-18s.
The 30-second answer: just four ingredients
If you flipped over any legitimate bottle of vape juice, the ingredient list would boil down to this:
- Propylene glycol (PG): the thin flavour carrier that gives throat hit.
- Vegetable glycerine (VG): the thick base that makes the visible vapour.
- Flavourings: food-grade concentrates that create every taste, from mango ice to classic tobacco.
- Nicotine: optional, and present in most but not all e-liquids.
That is it. No tobacco leaf, no tar, no ash, no combustion products. The PG and VG base alone makes up roughly 80 to 97 percent of the liquid by volume, with flavourings and nicotine making up the rest. Some bottles also contain small amounts of water. When your coil heats the liquid, the base vaporises and carries the flavour and nicotine with it, producing the aerosol you inhale. If you are shopping for your first kit, the best disposable vapes all use exactly this four-ingredient recipe.
Meet the ingredient: PG, the flavour courier
Propylene glycol is a thin, colourless, nearly odourless liquid that has been used in food, medicines, cosmetics, and pharmaceutical inhalers for decades. In vape juice, its job is delivery. PG carries the flavour molecules and the nicotine from the bottle to your taste buds, which is why high-PG liquids taste sharper and more defined.
PG is also responsible for most of the "throat hit," that tactile kick at the back of the throat that smokers recognise from cigarettes. Its thin consistency means it wicks quickly into small coils, which is why slim pod kits and starter devices perform best with PG-heavy liquids. A small minority of vapers find PG slightly irritating to the throat, and for them, high-VG blends exist as an alternative.
Meet the ingredient: VG, the cloud factory
Vegetable glycerine comes from plant oils and is the thick, faintly sweet member of the pair. If PG is the flavour courier, VG is the visual spectacle. It is VG that turns into the dense, white vapour you can actually see, so juices with more VG produce bigger, smoother clouds and a gentler draw on the throat.
That thickness comes with a practical catch. VG is syrupy compared to PG, so it needs wider wicking ports and more heat to vaporise cleanly. Put a very high-VG liquid in a tiny pod coil and it may not wick fast enough, giving you burnt-tasting dry hits. This is why cloud-chasing sub-ohm tanks and high-VG bottles are made for each other.
If the ingredient list has you weighing up switching from cigarettes altogether, our cigarettes vs vaping comparison walks through what each one actually puts into your body.
Meet the ingredient: nicotine, the optional one
Nicotine is the ingredient people have the most questions about, and it is the only one that is genuinely optional. Plenty of bottles come in 0mg versions with the exact same PG, VG, and flavouring base, minus the nicotine entirely. Nicotine is the addictive substance in tobacco, and the reason most smokers use vapes is to keep getting it without the smoke.
It comes in two forms, and the difference matters more than most people realise:
- Freebase nicotine is the classic form. It delivers a noticeable throat hit that gets harsh as the strength climbs, which is why high-strength freebase liquids can feel scratchy.
- Nicotine salts are nicotine treated with an acid, usually benzoic acid, which smooths out the throat hit at higher strengths. Nic salts at 20mg feel far softer than freebase at the same strength, which is why they became the default in pod kits and disposables aimed at ex-smokers.
Strength is capped by law in the UK: nicotine-containing e-liquid cannot exceed 20mg per millilitre and is sold in 10ml bottles. In the US, disposable vapes commonly go up to 50mg. Heavier smokers usually start higher and step down over time, while someone vaping 0mg keeps the ritual with zero nicotine. If you are curious about alternatives, our explainer on nicotine or Metatine covers the newer nicotine-like compound showing up in some products.
Meet the ingredient: flavourings, the personality
Flavourings are what turn a bland base into blue raspberry ice, vanilla custard, or icy menthol. They are food-grade flavour compounds of the same kind used in food manufacturing, typically suspended in a PG base before blending into the bottle. This is where the enormous variety of vape juice comes from, with thousands of profiles across fruit, dessert, menthol, tobacco, and drink-inspired categories.
One honest detail: the sweetness in many juices does not come from sugar. E-liquids contain no sugar at all. Sweetness comes from the flavourings themselves and sometimes from sweetener additives, which can gunk up your coils faster. If your coils die young, an overly sweetened juice is often the culprit. For a taste of how much variety is out there, browse our SBX flavour rankings with notes on all 13 flavours.
What is NOT in vape juice (myth-busting time)
Now for the ingredients that never made it into the bottle. Clearing these up matters, because most vape scares trace back to one of them.
There is no tar. Tar is a product of burning tobacco. Nothing in a vape is burned, so nothing in the vapour contains the tar that coats a smoker's lungs.
There is no tobacco leaf. Nicotine is extracted from tobacco plants during manufacturing, but the leaf itself, along with its thousands of combustion chemicals, never enters the bottle.
There is no oil. Despite the word "juice," e-liquid is water-soluble and oil-free. This distinction is important: the serious lung injuries reported in 2019 (the EVALI outbreak) were linked to vitamin E acetate, an oil-based thickener found in illicit THC cartridges, not in standard nicotine e-liquids from legitimate brands.
There is no ash or carbon monoxide. Both are products of combustion. A vape heats liquid into an aerosol; it never sets anything on fire.
There is no sugar. Covered above, but worth repeating, because the sweet taste fools almost everyone at first.
Knowing what is absent is also how regulators judge products, which is why checking the FDA-authorized vapes list is a smart habit before buying anything new.
The PG/VG ratio decoder
That "50/50" or "70/30" printed on the label is the PG/VG ratio, and it is the single biggest predictor of how a juice will vape. Here is how to read it at a glance:
| Ratio (VG/PG) | Vapour | Throat hit | Flavour | Best for |
|---|---|---|---|---|
| 50/50 | Modest | Strong | Sharpest | Pod kits and starter devices, ex-smokers wanting a cigarette-like hit |
| 60/40 | Medium | Medium-strong | Sharp | All-rounders, most pod systems |
| 70/30 | Dense | Mild | Good | Sub-ohm tanks, smoother draw with solid clouds |
| 80/20 | Very dense | Very mild | Slightly muted | Cloud chasing, direct-to-lung vaping |
| Max VG | Maximum | Smoothest | Softest | Cloud competitions, vapers avoiding PG |
The pattern is simple: more PG means more flavour punch and throat hit, more VG means more vapour and smoothness. Match the ratio to your device. Small coils want thinner 50/50 juice, big sub-ohm tanks want thicker high-VG juice.
How to read an e-liquid label like a pro
Legitimate e-liquid labels are regulated, and they tell you a surprising amount once you know what to look for. In the UK, nicotine-containing e-liquid must be notified to the MHRA, sold in bottles no larger than 10ml, and capped at 20mg/ml nicotine. Packaging must be child-resistant and tamper-evident, and labels must carry a nicotine warning alongside the ingredient list, batch number, and expiry date.
In the US, e-liquids sold as tobacco products must carry the FDA's required warning: "WARNING: This product contains nicotine. Nicotine is an addictive chemical." Legitimate bottles also list ingredients, net quantity, and the manufacturer.
Red flags that should stop you buying: no ingredient list at all, no nicotine warning on a nicotine product, no manufacturer name or address, no batch number or expiry date, or a bottle size that breaks local rules. A label that hides information is telling you something. Price can be a clue too, though taxes keep shifting the numbers, as our breakdown of the UK vape tax explains.
Frequently asked questions
Is there water in vape juice? Small amounts, yes. Water can appear as a minor component to adjust the consistency, but the liquid is overwhelmingly PG and VG.
Does vape juice contain antifreeze? This is the most common myth, and it comes from the name "propylene glycol" sounding like "ethylene glycol," the toxic chemical in antifreeze. They are different substances. PG is used in foods, medicines, and asthma inhalers. Still, the shared name is why the rumour refuses to die.
What is the difference between freebase nicotine and nic salts? Freebase gives a stronger throat hit and gets harsh at higher strengths. Nicotine salts are smoothed with an acid so they stay comfortable at high strengths and satisfy cravings faster, which is why they dominate pod kits and disposables.
Can I vape 0mg juice forever? The bottle will taste the same minus the nicotine, and many vapers step down to 0mg as a final stage. Whether you keep vaping at 0mg is a personal call, but the option exists precisely for that purpose.
Does e-liquid expire? Most bottles carry a shelf life of one to two years. Over time, nicotine oxidises, the liquid darkens, and the flavour can turn muted or peppery. Store bottles cool and dark, and check the expiry date before use.
Can I be allergic to PG? True allergies are rare, but some people are sensitive to PG and get a scratchy throat or mild irritation. Max-VG and 100 percent VG liquids exist for exactly this situation. If symptoms persist, stop and talk to a doctor.
Does the flavour affect the price? The bottle price depends far more on size, nicotine strength, brand, and taxes than on the specific flavour. For a full breakdown, see our vape juice prices guide.
The bottom line
A vape contains four things: PG, VG, flavourings, and optionally nicotine. The base does the heavy lifting, the flavourings provide the personality, and the nicotine is there for adult smokers who want it, in a form and strength that suits them. Everything else on the label, the ratio, the warnings, the batch number, exists so you can buy with your eyes open.
That knowledge is the difference between grabbing whatever looks colourful and choosing a juice that fits your device, your throat, and your goals. For more straight answers on the vaping world, keep exploring VapeFeat, and remember: if you don't smoke, don't start vaping. If you do smoke, now you know exactly what is in the alternative.