There are a few things to consider when deciding between using Propylene Glycol (PG) or Vegetable Glycerin (VG) in your e-cigarette. These two liquids are referred to as e-cigarette liquid or colloquially as e-juice, and both are considered safe for consumption by the FDA. PG is actually used in toothpaste and asthma inhalers, while VG is used to make theatrical fog and food products such as gummy candies. PG or VG are two of the four main components that go into e-cigarette liquid, the other two being nicotine, and food grade flavouring. PG or VG form the base that allows the nicotine and flavour to be held in suspension so that e-cigarette vapers can inhale and exhale vapour.
So what are they?
Propylene Glycol is a byproduct of petroleum while Vegetable Glycerin is a natural chemical derived from vegetable oil. Both substances belong to the alcohol chemical class, but they are not intoxicating, and you cannot become intoxicated by smoking an e-cigarette. Sometimes both PG and VG are incorrectly referred to as oils, but they are not oils and will not cause the medical issues that are associated with inhaling oils. What they are, are liquids that, when heated and vaporized, allow them to be inhaled.
Why PG and how is it unique?
PG is a thin liquid and can be absorbed by the cotton wick in the coil of the vaporizer tank. It has a low density and viscosity as well, which improves wicking through your cotton to prevent a build up of burnt residue in your coils, which means longer coil life and money savings for you. PG is has no flavour of its own and it helps carry flavours better which is great for those who enjoy experiencing vivid flavours, whereas VG can affect the intensity of added flavouring. Although PG allergies are very rare, PG can cause allergic reactions in those who ingest or inhale it. These include minor reactions such as a throat irritation, or more serious irritations around the body, depending on the severity of the allergy. If you ever experience any of these symptoms then talk to your doctor and stop vaping if they determine it is a PG allergy. For minor sensitivities to PG, you should switch to a higher VG eliquid to prevent throat irritation.
Why VG and how it is unique?
VG is thicker and has a slower cotton-absorption rate than PG. Because it is thicker than PG, it does accumulate more burnt residue around the heating element in your e-cigarette, which means replacing coils a little more often. VG also has a slightly sweet taste to it and doesn’t carry flavourings as well as PG, so this often requires the use of higher flavouring concentrations to achieve desirable results. It is also a flavour in its own right that some individuals enjoy on its own. While it is less allergenic than PG, almost all people will be fine consuming VG, but it can cause undesirable phlegm build up for some heavy users. The vapour from VG is thicker than PG, and there is more of it at a given power level, which makes produces more vapour volume. It also provides a smoother feel on your throat when vaping than PG.
To sum it up
Higher PG eliquid, with its more pronounced “throat hit,” vapes with a more similar feel to a cigarette which some may prefer, but higher VG eliquid produces more vapour and a smoother feel on your throat. For most people switching from cigarettes to e-cigarettes, it is good to start with higher PG eliquid because of the more familiar feel to cigarettes to help satisfy your craving.