April 29, 2022 5 min read

When you shop for vape juice at Simply ELiquid and other vape shops, propylene glycol (PG) and vegetable glycerine (VG) are two terms that you’re going to see constantly. They’re in the product descriptions that you read when looking at different e-liquids, and they’re even printed on the labels of most vape juices. There’s no way to escape PG and VG if you vape. What’s even more important is that they’re absolutely essential to the quality of your vaping experience – so you’d better know what they mean. So, what are VG and PG? They’re the two most plentiful ingredients in any bottle of vape juice, and you’re about to learn why it’s so important to keep PG and VG in mind when you buy e-liquid online.

What Are PG and VG?

Propylene glycol and vegetable glycerine are two of the world’s most common – and useful – chemicals. Although they’re created in different ways, they have several similar properties and can be used interchangeably in many applications. That’s one reason why they’re both used as e-liquid ingredients.

On that note, PG and VG aren’t just any e-liquid ingredients; they’re actually most of what’s in a bottle of vape juice. While the nicotine and flavours are certainly important, those ingredients are extremely concentrated in their original forms. They have to be diluted with a carrier in order for you to have a usable e-liquid, and PG and VG function as those carriers. At the most, the nicotine and flavours in a bottle of vape juice comprise around 10 percent of the bottle. The rest is PG and VG.

What Is Propylene Glycol (PG)?

Propylene glycol is a synthetic chemical, and it’s possible to derive it from a number of different sources including propylene oxide and even vegetable glycerine. It’s slightly more viscous than water, and it has almost no scent or flavour. Here are a few of its uses.

  • PG is an excellent solvent, so it’s used as a carrier for scents, flavours and even medications. You’ll find it, for example, in many asthma inhalers.
  • PG is an emulsifier that helps to keep liquid ingredients mixed. Its emulsification properties make it useful as an ingredient for products like cosmetics, lotions and haircare products.
  • PG inhibits microbial growth, so it’s used in air fresheners and deodorants.
  • PG attracts moisture from the air, so it’s used in some eyedrops.

What Is Vegetable Glycerine (VG)?

Unlike PG, vegetable glycerine is obtained naturally. It’s produced in the same chemical process that’s used to make soap. Adding lye to oil triggers a chemical reaction that produces soap and glycerine. If you use vegetable oil as the starting ingredient, you get vegetable glycerine in the reaction. It’s also possible to make soap and glycerine from animal fat, but animal-based glycerine isn’t used to make e-liquid. Here are a few of the ways in which vegetable glycerine is used.

  • VG tastes slightly sweet, so it’s used in some foods and beverages as a replacement for – or to augment – other sweeteners.
  • VG has emulsification properties similar to those of PG, so it can be used in place of PG as an emulsifier for lotions, cosmetics, shampoos and other topical products. VG works extremely well in those products because of its moisturising properties.
  • VG absorbs and traps moisture perhaps even more effectively than PG. Because it’s a powerful moisturiser that also tastes slightly sweet, it’s used as an ingredient in shelf-stable baked goods and other treats to help prevent those foods from going stale.

How Do PG and VG Affect Your Vaping Experience?

Now that you have a better understanding of what PG and VG are, it’s time to learn the answer to the question that probably brought you to this article in the first place. How do PG vs. VG compare when they’re used in an e-liquid? VG is slightly sweeter than PG, and it’s also significantly more viscous. Those properties can significantly affect the character of a vape juice.

Although e-liquids using only PG or only VG as their bases do exist, they aren’t common. The majority of the vape juices on the market use both ingredients in specific ratios – so the PG/VG ratio of an e-liquid is the thing that you need to know in order to get a better idea of how that e-liquid will perform with your vape kit. A higher-PG e-liquid will exhibit more of the qualities of propylene glycol, and high-VG products will exhibit more of the qualities of vegetable glycerine. You can also find 50/50 e-liquid – which is very common in nicotine salt vape juice – which exhibits the qualities of PG and VG in equal amounts.

Here are some of the ways in which the different PG/VG ratios will affect your vaping experience.

  • A high-PG e-liquid creates a slightly scratchy feeling in the throat, which helps to contribute to a strong throat hit. You might prefer a high-PG vape for a mouth-to-lung vaping scenario with a higher-nicotine e-liquid.
  • A high-VG e-liquid is very smooth and will have a slightly sweet flavour. If you prefer e-liquid with a lower nicotine strength, you may enjoy the fact that the VG enhances the inherent sweetness of the e-liquid’s flavour profile.
  • A high-PG e-liquid is thin enough to work in smaller vaping devices without causing dry hits. High-PG e-liquids will usually give you the best performance in small vape pens and pod systems.
  • A high-VG e-liquid is very thick and will generate large, voluminous vapour clouds. Because of the immense vapour production of high-VG e-liquids, people often choose VG-based vape juices for cloud chasing. High-VG e-liquids will usually give you the best performance if you use a high-end vape tank with a very low coil resistance.

How Safe Are PG and VG?

The question of whether PG and VG are safe is really just a small part of a much broader question: Is vaping safer than smoking? PG and VG have both been used as food additives for so long without ill effect that most health authorities consider them safe for that purpose. In addition, health experts such as Public Health England estimate that vaping is approximately 95 percent less harmful than smoking. However, the safety of inhaling PG and VG hasn’t been studied outside the context of vaping in general.

If you’re new to vaping, one thing you should know is that there are a few people in the world who are allergic or sensitive to PG. Because so many consumer products use PG – including many products that you consume or put on your skin – it’s very unlikely that you’d discover a PG allergy by vaping. If you’re sensitive to PG, you probably already know about it. If that’s the case, you should use only e-liquids that contain 100-percent VG.

What Is the Best PG/VG Ratio?

With most of the vaping devices on the market, you’ll enjoy excellent performance if you use an e-liquid with a 50/50 PG/VG ratio. With this PG/VG ratio, you’ll get the vapour production benefits of VG, but the e-liquid will still be thin enough to work with most small vaping devices. If you use a vape mod with a powerful tank, though, you may want to use an e-liquid with a higher percentage of VG in order to enjoy the biggest possible clouds.