Nicotine boosters are essential for adjusting the nicotine level in your nicotine-free e-liquids. These 10ml bottles of nicotine boosters, dosed at 20mg/ml nicotine, are designed to be added to shortfill, longfill or DIY e-liquids. Nicotine boosters make it easy to customise your e-liquid to suit your needs. You'll find two types of nicotine boosters: classic nicotine boosters and extra-fresh nicotine boosters, which add a freshness effect for a refreshing mouthfeel. Ideal for all your vaping preferences.