A friend of mine tried multiple times to switch to vaping.
He’d picked up an eGo-style device with a basic clearomizer and some e-juice, but vaping irritated his throat so much he couldn’t keep going.
He assumed the nicotine level was the issue. However, reducing it makes vaping less satisfying for a just-switching smoker. Plus, it didn’t seem to solve the problem for him anyway.
Time and time again, he went back to smoking.
When I found out about it, I conducted a little test. I took over a bunch of juices, varying in both nicotine content and PG/VG ratio, and let him try each. I didn’t tell him which was which. It probably didn’t matter, but I was in science mode and blinding the test just seemed right.
The results were clear-cut.
Higher-nicotine liquids with more VG didn’t bother his throat, but lower-nicotine liquids with more PG did. It was the PG bothering him, not the nicotine. After that, he went from being unable to vape for very long to being ready to start replacing smoking with the safer alternative.
He hasn’t looked back.
Although nicotine does have a role to play too, if you’re in a situation like this, it could be that the PG/VG ratio you’re vaping is causing the issue. In other words, you don’t need to give up on vaping yet.
But why did it make a difference? Why do most e-juices still use primarily PG if some people find it too irritating to vape? What are PG and VG anyway, and what’s the difference between them?
Here’s a run-down of the basics of PG and VG and some tips for finding your ideal ratio.
What is Propylene Glycol (PG)?
Propylene glycol is a colourless, almost odourless alcohol. It’s technical, chemical name is propane-1,2-diol. This tells you it has a backbone of three carbon atoms, with two oxygen-hydrogen (OH) alcohol groups attached to the first and second. It’s generally recognised as safe and is non-toxic. As a result, it’s used in a wide range of different consumer products.
It has many useful properties, including being a humectant (which means it helps to keep things moist), a preservative and a solvent. Because of this, it’s used in cosmetics, pharmaceuticals, human and pet foods, food flavourings and many other products. It’s also easy to vaporise, which has led to its use in asthma inhalers, theatrical fog machines and e-juice.
You can read more about what we know about the safety of inhaling PG in this article.
What is Vegetable Glycerine (VG)?
Like PG, vegetable glycerine (VG) is an alcohol. It’s colourless, odourless and sweet in taste, and more viscous than PG. It also has three “OH” alcohol groups instead of two, and it’s chemical name is propane-1,2,3-triol. You’ll often see it referred to as glycerol. As with PG, VG is non-toxic and generally recognised as safe to eat.
It also has a wide range of uses. This is thanks to its sweetness, it’s role as a solvent, the fact that it’s a preservative and its ability to help things retain moisture.
It’s used in pharmaceuticals (such as cough syrups, ointments and creams), cosmetics, things like hand cream and toothpaste, as a moisture-retainer in baked foods and as a solvent for things like food flavourings and colourings.
5 Key Differences Between PG and VG for Vapers
Based on their chemistry and applications, there are a lot of similarities between PG and VG. But there are also several key differences. These become important when you’re considering how much of each you want in your e-juice.
Here are five key points to consider when you’re making your choice.
1 – PG Gives a Stronger Throat Hit
One of the most important things to consider is that PG gives a stronger, more cigarette-like “throat hit.” This might not sound pleasant, but it’s actually a good thing for many just-switching smokers. It makes the feeling of vaping more like the feeling of smoking, which can ease the transition for new users.
But it isn’t a good thing for everybody. VG based e-liquid has a much smoother feeling on the throat, so anybody finding PG too irritating should choose juices with a higher VG content. Many longer-term vapers move towards higher VG content as a smoking-like throat hit becomes less important a factor.
2 – VG Improves Vapor Production
While VG may be lacking the throat hit many smokers are looking for, the biggest benefit is that it produces denser, thicker vapour. This is the reason that “cloud chasers” – who are looking to maximise vapour production – choose higher-VG e-liquids.
For newer vapers, having a high VG content and huge vapour production isn’t as important, but you still have to strike a balance. With little or no VG, the vapour production will be weak and the e-liquid won’t do as good a job of replicating the sensory experience of smoking.
This is one of the reasons that many beginner-friendly e-juices use about 40 to 60 % VG in their mixes. With a blend like this, the vapour production is substantial, but you don’t produce unnecessarily thick clouds. It also helps you avoid some of the downsides of high-VG e-juices while still enjoying the benefits.
3 – PG Wicks More Efficiently Than VG
One of the most important downsides of high-VG e-juices relates to how well it soaks into wicks. Because VG is much more viscous than PG, it takes a lot longer for it to soak into the wick and reach your coil. This can cause problems when you vape.
Every time you take a puff, you deplete the e-liquid in the wick, and it is replaced by the liquid in your tank. When you take the next puff, if your wick hasn’t re-soaked, you’ll get a “dry puff,” which tastes really nasty. Because PG is much thinner and soaks into the wick quickly, you’re less likely to run into this problem with higher-PG mixes. But for higher-VG mixes, it takes longer for the juice to re-soak the wick and dry hits are more likely.
In many modern sub ohm tanks, and especially in rebuildable atomizers, this doesn’t really matter. These devices have more effective wicking, so you won’t run into the same problems. However, if you’re using a basic clearomizer (for example, the Aspire BVC or Nautilus), high-VG juices could lead to performance issues.
4 – PG Carries Flavour Better
PG is generally better at carrying flavours than VG.
The difference is subtle, but it’s still a factor. Part of the reason for this is that VG is a little sweet but PG is near-tasteless, so VG interferes with the flavour of your e-liquid a bit more. If you tried the same e-liquid in a PG-based and a VG-based version, you’d notice the difference. But it must be stressed that the effect is fairly minor and hard to notice without a direct comparison.
You can also compensate by adjusting your settings to boost flavor if you have a variable wattage mod (see 10 Tips for Boosting Flavour). However, if you want to maximise flavour, PG-based e-liquids are still better.
5 – Some People are Sensitive to PG
Finally, some people are sensitive or even an allergic to PG.
Like my friend from the introduction, some vapers find PG intolerably irritating to the throat. This type of reaction is pretty rare, though. But it’s still something to keep in mind if you’re first trying vaping or if you’ve found vaping irritating to your throat in the past. It could be that you’ll need VG-based e-juices to start to enjoy vaping.
In most cases of PG sensitivity, you won’t need to completely remove PG to make vaping tolerable.
If you choose a higher-VG mix and pair it with a capable atomizer (like the Aspire Cleito or Anyvape Fury), you’ll probably find vaping a lot more enjoyable. If you need to go for a maximum VG blend, you’ll definitely need a high-quality, more advanced tank or atomizer. Most of the time, high-VG mixes are mixed with a little water to help with wicking, but they will still cause an issue with a basic clearomizer.
However, it’s worth stressing that some coughing is normal when you start vaping. So if you cough at first it doesn’t always mean you’re sensitive to PG. Most vapers report this issue clearing up with time.
A Brief Introduction to PG/VG Ratios
The PG and VG content of e-juices is expressed as a PG/VG ratio. This has the format “percentage PG/percentage VG.” So a 50/50 e-juice has equal amounts of PG and VG, and a 70/30 one has 70 % PG and 30 % VG.
A 70 % VG blend could be shown as 30/70, but sometimes (particularly with higher-VG juices), the order is reversed, so it could be shown as 70/30 VG/PG. Normally, the order of the two ingredients will be specified for clarity.
Making Your Choice: Which PG/VG Ratio is Right for You?
So now you know the benefits and limitations of PG and VG-based e-juices, the question is: which ratio is right for you?
The decision you have to make comes down to personal preference. Do you want big clouds? Do you think you’ll need a cigarette-like throat hit? Do you need to keep the VG content quite low so your clearomizer’s wick will soak it up effectively? If you can answer these questions, you’ll have a good idea which ingredient you should prioritise.
However, the standard PG/VG ratio is fast becoming 50/50. As you’d expect, this offers a nice balance of the benefits of each ingredient, so it keeps most vapers happy. Most vapers won’t want to stray too far from this ratio, with anything from 70/30 to 30/70 being in the normal range.
Our own Halo UK e-liquid used to be 60/40 PG ratio – a little more PG than VG. However, we are now moving all our e-liquids over to a 50/50 range. This still provides great vapour production, but also maintains efficient wicking and offers a solid throat hit.
The best advice is to try something in the standard range and see what you think, and then you can base your next decision on your experience. For example, you might find wicking problems with the e-liquid you bought. If this happens, you can switch to a higher-PG blend better suited to your equipment.
The only time it’s recommended to stray too far from the usual range is if you have a specific reason. A PG sensitivity is a great example, but you might also be looking for a stronger throat hit (and a higher-PG e-liquid) or better vapour production (and a higher VG one).
Give it Time; You’ll Find Your Ratio!
This might all sound a bit complicated, but don’t worry too much. The only times it’s more than a personal preference is if PG doesn’t agree with you or if you need a smoking like throat-hit to replace cigarettes. Most vapers are happy with anything in the usual range. We may have preferences, but we’re hardly strict. Just explore the options and experiment a little; you’ll find something that satisfies you in no time.