To deliver the vapour and flavour, e-cigarettes use e-liquid. It’s very important that e-cigs replicate the nicotine ‘hit’ of traditional cigarettes so smokers can properly adjust. The heating component of the e-cig vaporises the e-liquid and creates inhalable vapour. There are four key ingredients in e-liquid: vegetable glycerin (VG), propylene glycol (PG), nicotine and flavouring. Vegetable Glycerin Vegetable glycerin is a clear, odourless liquid that has a similar texture to oil or syrup. An organic compound extracted from plants, VG is widely used in food, medicine, and pharmaceutical industries. The food industry uses VG as a sweetener and food-thickening agent and cosmetics companies use VG in products like moisturisers, shampoo and toothpaste. Contrary to some wayward reports, VG is not toxic and is approved by the Food and Drug Administration (FDA). VG provides vapers with a sweet taste, giving users an experience similar to that of cigarettes. Propylene Glycol Propylene glycol is an odourless liquid mixable with water and you probably encounter it daily without even knowing. Commonly used in smoke machines and air-con units, PG is found in moisturisers, shampoo, toothpaste, hand sanitisers, fragrances and more. There are some misconceptions that PG is a toxic in anti-freeze products. But PG is often confused with ethylene glycol, which is a toxic ingredient in anti-freeze products. Like VG, PG is classified as safe by the FDA and it is used medically in inhalers, medicinal drugs, cough syrup and more. PG has a thin consistency and is easily absorbed, producing little gunk. It provides a stronger throat hit for users than VG. As PG collects moisture, it can make a user’s throat dry after use. There have been reports of allergic reactions to PG. If you experience any rashes or sweats, you should consult a medical professional. PG vs. VG Vaping The e-liquid content of PG and VG can be varied to suit the taste and needs of vapers. If a heavy smoker is considering a switch to vaping, an e-liquid with heavy PG content would soften the blow due to its superior nicotine hit. A PG-heavy e-liquid will also incur fewer gunks on e-cigarettes, and will therefore be less of a job for vapers to maintain them. E-liquids with a large VG content will be thicker and denser and some vapers will prefer that. VG-heavy e-liquids are sweeter and some vapers like a sweet flavour. Mixing the e-liquids may the best way to enjoy vaping, incorporating all of the positives of each. Combining the two will provide a balanced vapour density, good flavour intensity and adjustable throat hit levels. The content of each can be adjusted making e-liquids flexible and viable for all vapers. For nicotine strength recommendations, check out our guide.