Nicotine Guide: Salts vs Freebase, Strengths, Shortfills & Device Matching

Introduction

Choosing the right nicotine format and e-liquid blend can feel overwhelming, especially with so many options on UK shelves. This guide breaks down everything you need to know, from nicotine salt versus freebase to shortfills, nic shots, PG/VG ratios and device compatibility, so you can make an informed choice and get the best experience from your vape.

Nicotine Salts vs Freebase Nicotine: What's the Difference?

Freebase Nicotine

Freebase is the traditional form of nicotine used in most e-liquids. It has a higher pH, so it feels harsher on the throat at higher strengths. At 3mg to 6mg it suits sub-ohm devices; at 11mg to 18mg in 10ml bottles it also works in mouth-to-lung (MTL) pod kits for vapers who like a sharper throat hit.

  • Available strengths: 3mg to 6mg in shortfills after adding nic shots; 3mg to 18mg in 10ml freebase e-liquids
  • Best for: sub-ohm tanks and mesh coils at low strength; MTL pod kits at 11mg to 18mg
  • Throat hit: more pronounced at higher mg
  • Flavour: excellent at low strengths with high VG blends

Nicotine Salts

Nicotine salts use benzoic acid to lower the pH of nicotine, so higher strengths feel much smoother. They are absorbed faster than freebase, which makes them popular with vapers switching from smoking.

  • Available strengths: typically 5mg, 10mg and 20mg (20mg is the UK legal maximum)
  • Best for: pod kits, mouth-to-lung (MTL) devices, low-wattage vapes
  • Throat hit: noticeably smoother than freebase at the same strength
  • Nicotine satisfaction: faster and more pronounced per puff

Browse our 10ml nic salts in a wide range of flavours, and our nicotine shots and nic salt boosters for shortfills.

Which Should You Choose?

Factor Freebase Nicotine Salts
Device type Sub-ohm at 3mg to 6mg; MTL pod at 11mg to 18mg Pod / MTL / low power
Strength range 3mg to 6mg (shortfills); up to 18mg (10ml bottles) 5mg to 20mg
Throat hit Stronger Smoother
Nicotine speed Slower absorption Faster absorption
Best for Cloud chasers, experienced vapers Smokers switching, pod users

Common Nicotine Strengths Explained

UK regulations (TPD/TRPR) cap nicotine-containing e-liquid at 20mg/ml in bottles up to 10ml. Here's a practical guide to the common strengths you'll come across:

0mg (Nicotine-Free)

Zero nicotine. Found in shortfills before a nic shot is added. Also used by vapers who have stepped down from nicotine but still enjoy the flavour of vaping.

3mg

The most common sub-ohm strength. It is what you get when you add one 18mg nic shot to a 50ml shortfill, or two to a 100ml shortfill.

6mg

A mild-to-moderate strength for sub-ohm vapers, or a light strength for MTL devices. Available in 10ml freebase bottles, or by adding two 18mg nic shots to a 40ml shortfill.

10mg to 12mg

Available in both freebase and salt formats. Popular with MTL vapers on lower-powered devices and with moderate smokers switching to vaping.

18mg to 20mg

20mg is the maximum legal strength in the UK and is usually a nicotine salt; 18mg is the strongest common freebase. Suited to heavier smokers making the switch, in low-powered pod kits with a tight draw.

Shortfills & Nicotine Shots: How the System Works

UK regulations do not allow nicotine-containing e-liquid in bottles larger than 10ml. Shortfills are the practical solution: a larger bottle (60ml, 120ml and so on) filled with 0mg e-liquid, leaving space to add a separate 10ml nicotine shot.

The Maths Made Simple

  • 50ml shortfill + one 10ml 18mg nic shot = 60ml at 3mg
  • 40ml shortfill + two 10ml 18mg nic shots = 60ml at 6mg
  • 100ml shortfill + two 10ml 18mg nic shots = 120ml at 3mg

Nic shots are sold at a maximum of 20mg in the UK, so to get a higher strength you add more shots to less e-liquid rather than a stronger shot. For a step-by-step guide, see how to add a nic shot to a shortfill.

Nic Salt Boosters in Shortfills

You can also add nicotine salt boosters to shortfills if you want a smoother hit at your target strength. This is particularly useful for vapers who find freebase nic shots harsh.

Shop our shortfill e-liquids, including 100ml shortfills and 50ml shortfills, and stock up on nicotine shots and nic salt boosters to complete the mix.

50/50 vs 70/30 Blends: PG & VG Explained

Every e-liquid is a blend of Propylene Glycol (PG) and Vegetable Glycerin (VG). The ratio significantly affects your vaping experience.

What is PG?

PG is a thin, odourless liquid that carries flavour efficiently and produces a noticeable throat hit. It is a major part of 10ml nicotine salt bottles and 50/50 e-liquids.

What is VG?

VG is a thicker, slightly sweet liquid responsible for vapour production. High-VG e-liquids produce dense clouds but need more power to vaporise, which is why they are paired with sub-ohm coils.

50/50 (Equal Parts PG & VG)

  • Thinner consistency, suitable for MTL devices and pod systems
  • Stronger flavour and throat hit
  • Less vapour production
  • Works well at lower wattages (8 to 15W)
  • Common format for 10ml nicotine salt bottles

Browse our 50/50 e-liquids.

70/30 (70% VG, 30% PG)

  • Thicker consistency, needs sub-ohm hardware to wick properly
  • Larger, denser clouds
  • Smoother inhale with less throat hit
  • Best at higher wattages (30 to 80W+)
  • The standard ratio for most shortfill e-liquids

Explore our 70/30 high VG e-liquids.

Quick Comparison

Feature 50/50 70/30
Vapour production Low to moderate High
Throat hit Moderate to strong Smooth
Flavour intensity High Moderate to high
Device requirement Pod / MTL Sub-ohm / high wattage
Typical nicotine format Salts or freebase (10mg to 20mg) Freebase (3mg to 6mg after mixing)

Matching Your Choice to Your Device

The most important rule in vaping: always match your e-liquid to your hardware. The wrong combination can lead to dry hits, coil flooding or an unsatisfying nicotine experience.

Disposable Vapes and Their Replacements

Single-use disposable vapes have been banned from sale in the UK since 1 June 2025. Most of them used 20mg nicotine salt in a 50/50 or high-PG blend. If you used to vape disposables, the closest match is a rechargeable pod kit with 20mg nic salt. Browse our disposable vape alternatives, or read about the disposable vape ban and the best rechargeable alternatives.

Pod Kits & MTL Devices (8 to 20W)

  • Recommended e-liquid: 50/50 blend or high-PG nicotine salts
  • Recommended strength: 10mg to 20mg
  • Format: 10ml nic salt or 10ml freebase bottles
  • Why: Low wattage means thin liquids wick best; a higher strength delivers satisfaction per puff without needing a large volume of vapour

Shop pod kits and replacement pods.

MTL Sub-Ohm & Starter Kits (15 to 30W)

  • Recommended e-liquid: 50/50 or 60/40 blends
  • Recommended strength: 6mg to 10mg freebase or 10mg salt
  • Format: 10ml bottles, or a shortfill with nic shots
  • Why: Moderate airflow and wattage suits thinner liquids and mid-range strengths

Shop starter vape kits.

Sub-Ohm Tanks & High-Wattage Mods (40W+)

  • Recommended e-liquid: 70/30 or max-VG shortfills
  • Recommended strength: 3mg to 6mg freebase only
  • Format: 100ml shortfill + nicotine shots
  • Why: High vapour output delivers nicotine efficiently at low concentrations; 20mg salts on a sub-ohm device would deliver far too much nicotine per puff

Important: Never use high-strength nicotine salts (10mg to 20mg) in a sub-ohm device. The volume of vapour produced means you would take in far more nicotine than intended.

Quick-Reference Summary

Vaper Type Device E-Liquid Type Strength Blend
Smoker switching Pod kit Nicotine salt 20mg 50/50
Casual MTL vaper Pod / MTL kit Nic salt or 10ml freebase 10mg to 20mg 50/50
Experienced MTL MTL sub-ohm Freebase 6mg 50/50 to 60/40
Cloud / sub-ohm Sub-ohm mod + tank Freebase 3mg to 6mg 70/30 shortfill
Nicotine-free Any 0mg shortfill 0mg 70/30 or 50/50

Frequently Asked Questions

Can I mix nicotine salts with a shortfill?

Yes. Nic salt boosters are designed for this. Adding a nic salt booster instead of a standard freebase nic shot gives you a smoother throat hit at the same strength, a popular choice for those who find freebase harsh.

Is 20mg too strong for me?

That depends on your device and how much you smoked. On a pod kit with a tight draw, 20mg delivers a controlled amount of nicotine per puff, comparable to what many smokers are used to. On a sub-ohm device 20mg would be far too strong; stick to 3mg or 6mg there.

What happens if I use a 70/30 shortfill in a pod kit?

High-VG liquids are too thick to wick properly in the small coils found in pod kits. This usually means dry hits, burnt coils and poor flavour. Use a 50/50 blend in pod devices.

How do I know which blend is in my shortfill?

It will be stated on the label or product page. Most 100ml shortfills are 70/30; 50ml shortfills are commonly 70/30 or 50/50. Check before you buy if your device is lower-powered.

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This guide is intended for adults who already use nicotine products and are looking to switch to or continue vaping. If you have questions about nicotine and your health, speak to a healthcare professional. You must be 18 or over to buy vaping products in the UK.

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