What Is PG In Vape Liquid?
A clear UK guide to PG in vape liquid, what it does, why it produces throat hit and what PG sensitivity feels like.
PG (propylene glycol) is the thin neutral base that carries flavour and produces throat hit.
PG is one of two main e-liquid bases alongside VG. It is a thin colourless liquid used widely in food, theatrical fog machines and pharmaceutical inhalers. In vapes it carries flavour effectively and produces the throat sensation many ex smokers want. UK e-liquids typically mix PG with VG in ratios from 50/50 to 30/70.
PG is one of the most studied chemicals in vape e-liquid. It has been used safely in food and pharmaceuticals for decades. In vaping it does specific jobs: carrying flavour effectively, producing throat hit and keeping the liquid thin enough to wick well in low power devices. Understanding PG helps you choose the right e-liquid for your setup.
What PG actually does in your vape
Four functions explain why PG is in almost every e-liquid. The grid below covers each.
Flavour carrier
PG carries flavour molecules effectively, producing crisp clear taste profiles.
✓ Best for flavourThroat hit
PG produces the scratchy sensation that mimics cigarette throat feel.
✓ Cigarette likeWicking
PG is thin enough to soak quickly through coil cotton, suiting low power MTL devices.
✓ Low power friendlyStability
PG keeps nicotine and flavour stable in storage. Reduces flavour change over time.
✓ Long shelf lifeHow PG affects different vape setups
The table below covers how PG ratio matches device type.
| Device type | Recommended PG ratio |
|---|---|
| MTL pod system | 50/50 PG/VG suits most pod systems |
| Refillable MTL device | 50/50 PG/VG or 60/40 PG/VG for stronger throat hit |
| Sub ohm tank | 30 percent PG or lower (70/30 VG/PG) |
| Cloud chasing setup | 20 percent PG or lower (80/20 VG/PG) |
| High wattage mod | 30 percent PG or lower for cooler vapour and clouds |
PG sensitivity is real but uncommon
Around 5 percent of UK vapers experience PG sensitivity. Symptoms include sore throat, dry mouth, mouth ulcers, persistent cough or skin irritation. The fix is straightforward: switch to high VG e-liquid (70 percent VG or higher) which contains very little PG. Most UK vape shops stock dedicated high VG ranges for this reason. PG sensitivity tends to develop within the first few weeks of vaping if it is going to occur.
PG is on the UK Food Standards Agency Generally Recognised As Safe list. The same material is used in salad dressings, ice cream and asthma inhalers. The vaping context introduces inhalation which is the main area of ongoing UK research. PG itself is well understood. Acute toxicity from typical vaping intake levels is not a documented concern.
How to manage PG sensitivity
The checklist below covers what UK vape shop staff most often recommend.
PG sensitivity management checklist
Use four or more of these if PG appears to be causing issues.
- Switch to high VG e-liquid 70 percent VG or higher
- Try Max VG (100 percent) shortfills if symptoms persist
- Drink more water to manage dry mouth
- Avoid sweet flavours which can compound throat irritation
- Lower nicotine strength to reduce overall harshness
- Take a break for a few days to confirm PG is the cause
PG versus VG when picking e-liquid
PG and VG together make up the bulk of every e-liquid. Higher PG ratios suit MTL devices and ex smokers wanting throat hit. Higher VG ratios suit DTL sub ohm vapers wanting clouds. The choice depends on your device and personal preference. Most UK vape shop staff can guide you to the right ratio based on what device you use and what experience you want from your vape.
PG works alongside VG as the e-liquid base partnership, which our our guide on what is VG in vape liquid covers, plus our article on VG vs PG differences explained explains how PG affects throat sensation.
Frequently asked questions
Is PG safe to inhale?
PG has decades of safe use in food and pharmaceuticals. Inhalation research is ongoing but acute toxicity from typical vape exposure is not documented.
Can PG cause allergies?
True allergy is very rare. Sensitivity producing irritation is more common at around 5 percent of UK vapers.
Why is PG used in fog machines?
Same reason as vaping. PG vaporises cleanly and produces visible vapour. Theatrical use is the original commercial application.
Are there PG free vapes?
Yes. Max VG e-liquids contain little or no PG. UK vape shops stock these for sensitive users.
Does PG flavour the e-liquid?
PG itself is almost flavourless. It carries the added flavour compounds rather than tasting of anything itself.
Part of our Consumer Guides Hub
Get to grips with vape gear, hardware and how it works
Our consumer guides hub explains coils, batteries, e-liquid types, troubleshooting and everything else you need to know as a UK vaper.
Browse the Consumer Guides HubFor more on devices, e-liquid types and troubleshooting, our vape consumer guides hub brings the full collection together in one place.
