What Are VG and PG in an E-Liquid?

When you buy e-liquid online or offline, “VG/PG ratio” is a phrase that you’ll see often. Although you don’t have to understand all of the jargon in vaping to have a good experience, understanding VG and PG is actually quite important because those substances make up the majority of all e-liquids. The ratio of those substances affects everything from the mouth feel of the vapor to the types of vaping equipment that will work well with an e-liquid. It’s time for you to up your vaping game! Let’s learn more about VG and PG and discover how the ratio of these two liquids can dramatically alter your experience.

What Are VG and PG?

When you think about e-liquid, flavor profiles are probably the first things that come to your mind. Nicotine might be the second thing. The fact is, though, that flavors and nicotine comprise only a few percent of an e-liquid’s total contents. The rest is vegetable glycerin, propylene glycol or, more commonly, a blend of the two. VG and PG dilute the flavors and nicotine to their proper strengths. They also hold the other ingredients of an e-liquid in suspension, so you don’t need to shake your e-liquid bottles constantly while vaping. When you exhale after puffing on an e-cigarette, clouds of VG and PG are what you see. As much as we focus our attention on the flavor profiles of different e-liquids, VG and PG are actually the majority of what you vape. That’s why it’s so important to understand how those substances affect your vaping experience.

Understanding Vegetable Glycerin

Vegetable glycerin is a clear liquid created in the soapmaking process. If you add a strong base such as lye to an oil, you get soap and glycerin. In foods, VG provides added sweetness. It also retains moisture and helps to keep shelf-stable products from going stale. In beauty products, VG is an emulsifier and natural moisturizer.

In e-liquids, VG lends its inherent sweetness to any flavor profile. It’s one of the reasons why an e-liquid can taste sweet even if it contains no added sweeteners. The downside of that sweetness, though, is that the individual flavor notes in an e-liquid can be a little difficult to pick out if the e-liquid contains mostly VG.

VG is thicker than PG. When you vaporize it, VG creates large vapor clouds that can sometimes hover in a room for several minutes. The thickness of the liquid also means that a vapor cloud containing mostly VG will have a full, silky mouth feel. One drawback of VG’s thickness, though, is that a high-VG e-liquid doesn’t work well with a very small e-cigarette. A high-VG e-liquid can only flow efficiently through an atomizer coil with large wick openings.

Understanding Propylene Glycol

Propylene glycol is a synthetic product, but it often comes from a natural source such as corn oil. Like VG, PG is often used as a preservative in foods and as an emulsifier in cosmetic products. Smoke machines usually work by vaporizing PG. PG is also a common ingredient in medical inhalers.

In e-liquids, PG tends to enhance throat hit. Compared to VG, PG has a flavor that’s more difficult to detect. A high-PG e-liquid, therefore, allows the notes in an e-liquid’s flavor blend to come through more clearly. PG has little sweetness of its own, so it works best with flavor profiles – such as tobacco flavors – that are meant to be savory. Creating a sweet flavor profile in a high-PG e-liquid isn’t easy.

PG is much thinner than VG. When you vaporize it, PG creates light vapor clouds that disappear quickly. Since PG is very thin, it doesn’t provide much enhancement to the mouth feel of an e-liquid. Inhaling vaporized PG is a bit like inhaling water vapor. The fact that PG is so thin means that a high-PG e-liquid can work very well in an e-cigarette that has small wick openings. The smallest e-cigarettes – such as cigalikes and pod vaping systems – often work best with e-liquids containing at least 50 percent PG.  Since PG is thin and vaporizes quickly, a high-PG e-liquid doesn’t work well in a sub-ohm vaping system designed for high-temperature operation.