Longfill vs Nic Salts Difference in Strength and Feel
Longfill vs nic salts:
strength
& feel
Two delivery formats, two very different sensations. Freebase longfills deliver classic throat hit at 3-9mg. Nic salts deliver smooth high-strength absorption at 10-20mg. This is the UK guide to which one suits your vape style.
Freebase longfills deliver classic throat hit at lower strengths (3-9mg). Nic salts deliver smooth absorption at higher strengths (10-20mg). Same nicotine molecule, different chemistry. Freebase suits sub-ohm clouds plus experienced vapers who want a satisfying kick. Nic salts suit pod kits plus ex-smokers who want strong delivery without the harsh throat. The good news: Nixer offers both formats through different Mixer Kits using the same flavour concentrates. Pick the feel you want without changing your flavour.
Three numbers
that separate the formats
Freebase range, nic salt range plus the shared legal cap. The distance between them is the key.
Typical freebase range
Longfills mixed with freebase kits settle at 3mg, 6mg or 9mg for most vapers. Sharp classic throat hit.
Typical nic salt range
Nic salts comfortably deliver higher strengths without harshness. 10mg is the most popular UK pick.
UK legal cap
The TPD nicotine strength cap for any format sold in the UK. Both freebase plus salt respect the same ceiling.
Same molecule. Different chemistry. Very different feel.
Both freebase nicotine plus nic salts contain the same active molecule: nicotine. What differs is the chemistry around it. Freebase nicotine is the pure unbonded form used in traditional e-liquids since the beginning of vaping. Nic salts are nicotine bonded with an organic acid (typically benzoic acid). The bonded form changes how the nicotine passes through your throat plus how fast it absorbs into your bloodstream.
The practical result is that nic salts feel smoother at high strength. A 20mg nic salt vape produces a gentle hit that ex-smokers find pleasantly similar to a cigarette draw. A 20mg freebase vape by contrast produces a sharp coughing-fit-inducing throat hit that most vapers find intolerable. This is why UK pod kits almost universally use nic salts at 10mg or 20mg, while sub-ohm mods use freebase at 3mg or 6mg.
The absorption difference is also meaningful. Nic salts hit your bloodstream faster through the mouth plus throat lining, producing a satisfying rush within 2-3 minutes. Freebase absorbs more gradually over 10-15 minutes for a slower steadier delivery. Ex-smokers typically prefer the faster nic salt rush because it mimics cigarettes more closely. Long-term vapers often prefer the slower freebase curve because they do not need the sharp peak.
Both formats available as Nixer longfills
Nixer manufactures both freebase Mixer Kits (at 3mg, 6mg, 9mg in 50/50 plus 70/30 ratios) plus nic salt Mixer Kits (at 5mg, 10mg in 50/50 ratio only). The same Nixer flavour concentrate bottle can become either a freebase or nic salt longfill depending which Mixer Kit you buy. The mixing process is identical. Three 10ml bottles into a 60ml concentrate bottle, shake plus mix. Only the chemistry of what is inside the three 10ml bottles changes.
A practical note: nic salt Mixer Kits are only sold in 50/50 VG/PG ratio because they are designed for pod plus MTL use, which both require 50/50 liquid. If you want a sub-ohm-compatible longfill, you can only get it as freebase 70/30. Nic salt 70/30 is an unusual combination that is not produced by any major UK brand because it pairs a high-strength nicotine with a high-power device, which results in far too much nicotine per puff.
- Freebase longfills. Classic throat hit. 3mg-9mg. Available 50/50 or 70/30.
- Nic salt longfills. Smooth high-strength. 5mg-10mg. Available 50/50 only.
- Same flavours. Every Nixer concentrate works with either Mixer Kit type.
- Same price. Freebase plus nic salt Mixer Kits cost the same from Nixer.
Where each format
sits on the nicotine scale
A visual mapping of freebase plus nic salt strengths against the UK 0-20mg range. Both formats can be mixed inside a longfill.
0mg to 20mg mapped by format
The coloured line shows the full UK legal strength range. Freebase (teal) sits at the lower end. Nic salts (purple) sit at the higher end. The amber middle is where both formats overlap.
Freebase comfort zone
Where most freebase vapers sit. Sub-ohm mods typically use 3mg or 6mg. MTL devices use 6mg or 9mg. Freebase above 9mg becomes uncomfortably harsh for most UK vapers.
Nic salt light zone
Lower-strength nic salts for casual pod use. Smooth delivery at 5mg or 10mg. Suits light vapers plus ex-smokers on gentler tobacco alternatives. The 10mg mark is the most popular UK nic salt strength.
Nic salt max strength
The UK TPD legal ceiling. 20mg nic salt delivers strong nicotine without freebase-style harshness. Popular with heavy ex-smokers. Not available as a Nixer Mixer Kit (we cap at 10mg to avoid over-delivery).
How each format hits
over time
Freebase plus nic salts produce very different nicotine delivery curves. This illustration shows why the experiences feel so different.
Sharp peak vs steady plateau
Illustrative curves showing typical nicotine blood plasma levels after vaping starts. Nic salts spike fast then fall. Freebase climbs slow then sustains longer. These shapes explain why each format feels different.
Nic salts: sharp early peak
Spike peak around 3 minutes. Sharp hit then decline. Mimics a cigarette draw curve. Suits cravings control plus ex-smokers.
Freebase: steady plateau
Gradual climb peaking around 15 minutes. Longer sustained feel. Suits all-day chain vaping at lower strengths.
Seven feel traits
compared
A direct head-to-head on the dimensions most UK vapers care about.
Pick freebase or nic salt
from any Nixer flavour
Every Nixer concentrate works with both Freebase (3-9mg) plus Nic Salt (5-10mg) Mixer Kits. Pick your flavour first, pick your feel second. Strawberry watermelon in freebase for sub-ohm or in nic salt for pod. Same taste, different throat experience.
Browse the full Nixer longfill collection and pick your Mixer Kit from the dropdown on each product page. Freebase plus Nic Salt options are listed side by side for every flavour. The mixing process is identical either way.
For more context on longfills including mixing walkthroughs, strength calculation plus device pairing, head to our complete Nixer vape review hub where every practical UK longfill question has its own in-depth article.
Back to the Nixer Vape Review hub
This article is one chapter in our complete Nixer knowledge base. Head back for the full index covering longfill basics, mixing, strength selection plus the format comparisons.
More on strength
& device pairing
For the direct cost comparison on whether longfills work out cheaper than nic salts across a full year of vaping, see are Nixer longfills cheaper than nic salts in the long run. For the strength maths covering exactly how each Mixer Kit produces the nicotine level it does, what strength can I make my Nixer longfill explains it clearly. Plus for the full VG/PG explainer which interacts with strength selection, how to choose the right VG/PG ratio for longfills has the detail.