How to Add Nicotine Shots to a Shortfill Correctly
How to add
nicotine shots to a
shortfill correctly
UK shortfills arrive nicotine-free by law. You add the nic shot yourself. Done right it takes under two minutes plus delivers consistent strength across the whole bottle. Here is the exact method Dispergo uses, verified against TRPR 2016 plus MHRA GBID notifications.
To add a nicotine shot to a shortfill correctly: remove the nozzle of the shortfill bottle, pour the full 10ml nic shot in, reattach the nozzle plus cap, shake hard for 30-60 seconds then let it settle for 2-3 minutes. A standard 50ml shortfill in a 60ml bottle takes one 10ml 18mg nic shot to reach 3mg/ml final strength. A 100ml shortfill in a 120ml bottle takes two. Match the VG/PG ratio of your nic shot to the shortfill for best results. Optional: steep 24-48 hours for maximum flavour development.
Three numbers
frame the method
TRPR bottle-size limit, typical UK nic shot strength plus typical final strength. Three numbers every UK shortfill mixer needs to know.
TRPR nic shot cap
UK law limits nicotine-containing e-liquid to 10ml per container under TRPR 2016. Shortfills exist to work around this.
Standard nic shot
The most common UK nic shot strength is 18mg/ml freebase. Nic salt shots run 20mg/ml which is the UK legal max.
Typical final strength
Standard shortfill maths delivers 3mg/ml final nicotine. 1 shot in 50ml shortfill. 2 shots in 100ml shortfill.
UK law limits nicotine e-liquid to 10ml bottles. Shortfills arrive nicotine-free in larger bottles with space left for you to add the nic shot yourself.
Understanding how to add nicotine shots to a shortfill correctly starts with understanding why shortfills exist in the first place. The Tobacco and Related Products Regulations 2016 (TRPR) restrict nicotine-containing e-liquid to a maximum container size of 10ml per bottle in the UK. For vapers who go through significant amounts of e-liquid each week, buying multiple 10ml bottles becomes expensive plus wasteful on packaging. Shortfills solve this by selling the e-liquid base nicotine-free in larger bottles (most commonly 50ml or 100ml) with headroom left at the top for the vaper to add a separate 10ml nicotine shot at home.
A 50ml shortfill actually comes in a 60ml bottle with 50ml of e-liquid plus 10ml of headspace. A 100ml shortfill comes in a 120ml bottle with 100ml of e-liquid plus 20ml of headspace. The empty space is by design, not a shortage. Nicotine shots are 10ml bottles of unflavoured nicotine-containing e-liquid at either 18mg/ml (freebase) or 20mg/ml (nicotine salt) strength. When you pour the shot into the shortfill, you fill the bottle to its stated volume plus activate the nicotine content. Simple maths, simple process, totally legal under MHRA rules.
This guide covers the correct mixing method Dispergo recommends based on our own UK manufacturing experience plus TRPR-compliant best practice. Following this method delivers consistent nicotine distribution across the entire bottle, preserves flavour intensity plus protects you from common mistakes that can ruin a bottle or dilute flavour unnecessarily. The whole process takes under two minutes plus requires zero specialist equipment beyond the bottles themselves.
What you need before mixing
Before you start mixing, have the following ready: your shortfill bottle, the correct number of nicotine shots for your target strength, a clean flat surface plus a paper towel or cloth. The paper towel is for catching any spills when you remove the nozzle or squeeze the nic shot in. For 50ml shortfills you need one 10ml nic shot. For 100ml shortfills you need two 10ml nic shots. Using 18mg freebase nic shots produces 3mg/ml final strength. Using 20mg nic salt shots produces 3.33mg/ml final strength (effectively 3mg for practical purposes).
A common question is whether to wear gloves. Gloves are recommended for higher-volume mixing (more than 2-3 shortfills at a time) but not strictly necessary for single bottles. Nicotine in the concentrations used in shots is absorbed through skin slowly. A small spill that you wash off promptly is not dangerous. Repeated spills without washing can cause nicotine sensitivity symptoms like nausea or dizziness so exercise caution. Keep all nic shots plus mixed shortfills out of reach of children plus pets at all times, which is a legal requirement under General Product Safety Regulations.
- Standard kit. Shortfill bottle, nic shots, paper towel, flat surface.
- 50ml shortfill. One 10ml nic shot to reach 3mg/ml.
- 100ml shortfill. Two 10ml nic shots to reach 3mg/ml.
- Safety. Wash any skin spills promptly. Keep out of reach of children.
The six-step
mixing method
Each step in sequence with the exact action plus timing. Follow these six steps for a perfectly mixed shortfill every time. Total time under two minutes for a single bottle.
The six-step sequence
Six numbered steps from opening the bottles through to final rest. Each step builds on the previous one. Skip no step. Diagram below plus detailed step cards underneath.
Remove the shortfill nozzle
Unscrew the childproof cap of the shortfill bottle. Prise the plastic nozzle tip off gently using your fingernail or a nozzle-removal tool. The nozzle pops back on after mixing. Keep it somewhere clean.
Pour the nic shot in
Unscrew the cap of the 10ml nic shot. Pour the entire contents into the shortfill opening. Squeeze the last drops out. For 100ml shortfills repeat with a second 10ml nic shot for 3mg/ml final strength.
Reattach the nozzle plus cap
Press the nozzle firmly back onto the shortfill bottle until it clicks. Screw the childproof cap back on tight. Check the seal by turning the bottle gently upside down. No leakage means a good seal.
Shake vigorously for 30-60 seconds
Hold the bottle upright plus shake hard for at least 30 seconds. Some vapers prefer 1-2 minutes for extra thoroughness. The shake distributes the nicotine evenly across the whole bottle. Skipping this step causes uneven strength.
Let the bottle rest
Stand the bottle upright on a flat surface for 2-3 minutes. Air bubbles settle out during this time. Pouring into your tank straight after shaking produces bubble-heavy wicks which cause harsh early puffs.
Vape or steep
Fill your tank plus start vaping. Or for maximum flavour development, leave the mixed bottle sealed in a dark cupboard for 24-48 hours. Steeping deepens the flavour profile. Shake once or twice during steep.
Nicotine strength
quick-reference chart
Every common UK shortfill plus nic shot combination mapped to the final strength you get. No maths needed. Find your shortfill size, find your shot count plus strength, read off the result.
Final mg/ml for every common combo
Horizontal rows show common UK shortfill sizes. Vertical columns show number of 10ml nic shots plus their concentration. Each cell shows the final nicotine strength in mg/ml once mixed plus shaken.
The five most common
mixing mistakes
UK vapers make the same five mistakes again plus again when mixing shortfills. Each row pairs the mistake with the correct approach. Get these five right plus your shortfill mixing will be flawless every time.
The five most common mixing mistakes
Each row shows the wrong approach on the left with the correct approach on the right. Red cross means do not do this. Green tick means do this instead.
Skipping the shake
Pouring the nic shot in plus going straight to vaping. The nicotine layers at the top of the bottle because it is less viscous than the flavoured base. First few tank fills deliver full strength. Later fills deliver zero nicotine.
Shake hard for 30-60 seconds
Hold the bottle upright plus shake vigorously for at least 30 seconds. Some vapers prefer 1-2 minutes. The shake distributes nicotine evenly so every tank fill has the same strength across the full bottle.
Mismatching VG/PG ratios
Using a 50/50 nic shot in a 70/30 high-VG shortfill. The ratio shift dilutes the vapour production plus changes the mouthfeel. The mix stays safe to vape but cloud output plus flavour consistency degrade noticeably.
Match VG/PG ratio exactly
Check the shortfill VG/PG ratio (printed on the label) plus use a matching nic shot. Max VG shortfill gets Max VG nic shot. 50/50 shortfill gets 50/50 nic shot. Consistency protects flavour plus cloud production.
Vaping straight after shaking
Filling the tank immediately after the 30-second shake. Air bubbles trapped in the liquid get drawn into the coil wick. First few puffs taste harsh, watery or produce spit-back because the wick is saturated with bubble-heavy liquid.
Rest the bottle for 2-3 minutes
Stand the shaken bottle upright on a flat surface for 2-3 minutes before filling the tank. The rest lets trapped air bubbles rise plus clear. First puffs come out smooth plus consistent.
Adding too many nic shots
Forcing an extra nic shot into a shortfill that only has room for one. The overflow spills over the rim. The bottle cannot reseal properly. Higher final nicotine strength becomes harsh on the throat plus wastes expensive nic shots.
Stick to the intended shot count
Use the shot count the shortfill was designed for: 1 shot for 50ml, 2 shots for 100ml. For higher target strengths, decant some of the shortfill base into a spare empty bottle before adding extra shots to make room.
Leaving shots unmixed for weeks
Buying shortfills plus nic shots in bulk then leaving some unmixed for weeks before adding the nicotine. Nicotine-free e-liquid stays stable but flavour quality degrades after 2-3 months of air exposure. Dates become confusing.
Mix when you open the bottle
Mix the nic shot in as soon as you open the shortfill for first use. Store unmixed shortfills sealed in a cool dark cupboard for up to 12 months. Label mixed bottles with the mix date for freshness tracking.
Shop Dispergo
Shortfills
Full shortfill range from Dispergo. 50ml plus 100ml bottles across every flavour category. TRPR-compliant. MHRA-notified. Matching nic shots available at checkout so you always leave with the right combo. Free UK delivery on orders over £20.
Browse the full Dispergo shortfill collection to find your next 50ml or 100ml bottle. All shortfills are TRPR-compliant plus MHRA-notified. Matching nic shots available alongside every bottle. Free UK delivery on orders over £20.
For more context on shortfills including strength selection, beginner guidance plus 100ml step-by-step, head to our complete Shortfill consumer guide hub where every practical question has its own article.
Back to the Shortfill Consumer Guide hub
This article is one chapter in our complete Shortfill knowledge base. Head back for the full index covering strength selection, device pairing, VG/PG matching plus comparison guides.
More shortfill
mixing guides
For the strength-selection decision that comes right after you know how to mix, see how to choose the right nicotine strength for your shortfill. For the specific 100ml walkthrough with a second nic shot, how to use a 100ml shortfill step by step covers the larger format. Plus for the foundational explainer of what shortfills actually are, what are shortfill e-liquids: a complete guide covers the basics.