# PG/VG and nicotine: the ratio moves the throat hit > The PG/VG ratio changes how nicotine feels at an unchanged figure. How to read it, why a shortfill shifts it, and when the label is not the culprit. Two bottles from the same range, the same figure on both labels, and one grips the throat while the other passes almost unnoticed. The single line separating them is the **PG/VG** ratio, and it does not alter a milligram of what is inside. It is the most expensive blind spot in this whole subject. When something feels wrong, the concentration is what gets blamed and the base is what actually changed. This note sets out how the ratio acts on nicotine, why British shelves make the problem worse than it needs to be, and how to work out which of the two is really responsible. ## What the PG/VG ratio describes The ratio gives the proportion of propylene glycol to vegetable glycerine in a liquid, and the two always total one hundred. A 50/50 holds equal parts, a 30/70 leans heavily towards glycerine, a 70/30 the other way. Almost every guide presents this as a vapour and flavour setting, which is true and incomplete. It is also an amplifier or a damper on the sensation nicotine produces, at a concentration that has not moved at all. Propylene glycol is thin, carries flavour compounds cleanly and sharpens the throat sensation. Vegetable glycerine is thick, faintly sweet, produces dense vapour and rounds that sensation off rather than pointing it. Nicotine follows whichever carrier it is in. On a propylene-heavy base it arrives defined and concentrated in a small volume of vapour. On a glycerine-heavy base the identical quantity spreads through more vapour and reads as gentler. ## Perceived dilution, not actual dilution There is a phrase worth borrowing for this: perceived dilution. The quantity per millilitre is exactly what the label says in both cases, guaranteed by the rules that require it to be printed. What changes is how much material that quantity is distributed through by the time it reaches you. More vapour, more air, more glycerine coating the sensation, and each mouthful reads as less pointed than it did. This is why a figure that felt correct in one liquid can feel thin in another from the same shelf. Nothing has been removed. The signal has simply been spread wider. Understanding that distinction is what stops the reflexive move up the scale, which is usually the wrong response to a change of base and only becomes the right one after everything else has been ruled out. ## Why a figure that worked at 50/50 falls flat at 30/70 The classic sequence runs like this. Someone settles at a 50/50, finds a flavour they want that only exists as a high glycerine shortfill, orders the same figure out of habit, and finds it lifeless. Three effects stack in that move. The propylene glycol share drops, so the throat sharpness dulls. Vapour volume rises, so the nicotine spreads. And flavour delivery becomes rounder, which removes the definition that was serving as a reference point. The instinct is to raise the concentration. It is not usually the first thing to try, and often not the right thing at all, because what went missing was sharpness rather than quantity. The reverse trips people up just as often. Moving from a glycerine-heavy liquid back to a 50/50 can make a previously comfortable figure feel abrasive, and again the label has not moved by a single milligram. ## How British shelves force the PG/VG ratio to change Britain has a market structure that makes this happen more often here than it needs to, and almost nobody frames it as a nicotine issue. Because bottles containing nicotine are capped at 10 ml, larger liquids are sold nicotine-free as shortfills, and those are overwhelmingly high glycerine, typically 70/30, because they are built for higher power devices. The nicotine shot added to them is sold separately and comes in its own ratio, commonly 50/50 or 70/30. The result is that a shortfill user is choosing two ratios and mixing them, then reading a final base that appears nowhere on either bottle. Adding a 50/50 shot to a 70/30 shortfill nudges the finished liquid towards propylene glycol, slightly, which is enough to change the throat sensation. At the other end of the shelf, bar-style salt liquids and pod-friendly ranges are near-universally 50/50, because thin liquid is what narrow, high resistance coils can wick. So the two ends of British retail sit at opposite ends of the ratio scale, and moving between them means moving both variables at once. ## Hardware chooses the ratio more often than you do The ratio is not really a free choice. It is largely dictated by the coil, which is why changing device almost always means changing base. A thin liquid in a coil designed for thick liquid tends to leak past the seals. A thick liquid in a narrow, high resistance coil struggles to reach the wick, which produces a burnt taste well before it produces a nicotine complaint. So compact pods and tight draw kits run on balanced or propylene-heavy liquids, while sub-ohm tanks run on glycerine-heavy ones. There is very little room to deviate. That is exactly why a concentration should always be read together with the hardware, as our note on [nicotine strength and your device](/uk/nicotine-strength-by-device/) sets out. The **PG/VG** ratio is the third dimension of that same equation, and it moves whenever the first two do. ## Isolating the variable The method is a single principle. When a sensation changes, change one thing, and give it time before judging. First, let the liquid settle. A glycerine-heavy base often needs a couple of tank fills before it delivers its stable character, and a verdict reached on the first mouthful is almost always wrong. Second, name precisely what is missing. If it is throat sharpness, that is a ratio question or a question of nicotine form, and our comparison of [nic salts and freebase](/uk/nic-salts-or-freebase/) covers the second of those. If what is missing is a diffuse satisfaction that persists across a session, that is a concentration question. Third, move one control. Look for the same flavour in a more propylene-heavy **PG/VG**, or change the form of nicotine, before touching the figure. The concentration comes last, once the other explanations are exhausted, and when it does come up the approach is the one set out in our note on [reading nicotine strength on the bottle](/uk/nicotine-strength-guide/), now read with the ratio in mind. ## The misreadings that recur Four errors account for most of the confusion, and they are worth naming. Believing a glycerine-heavy **PG/VG** contains less nicotine. It does not. The printed figure is a real figure whatever the base, and the rules require it to be accurate. Confusing throat hit with satisfaction. The hit is immediate and local, and heavily dependent on propylene glycol. Satisfaction builds across a session. A liquid can offer very little of the first while lacking nothing in nicotine. Comparing across ranges to judge a ratio. Flavour concentrates differ in intensity from one brand to another, which contaminates the comparison entirely. Ignoring the power setting. Raising the wattage on an unchanged tank increases vapour output, which shifts the sensation in exactly the direction a more glycerine-heavy base would. ## Frequently asked questions ### Does the ratio change how much nicotine is in the bottle? No. The concentration printed on the label is the same whatever the proportion of propylene glycol to vegetable glycerine. What changes is how that nicotine is perceived in the throat and how much vapour it is distributed through. ### Should the figure go up when moving to a high glycerine liquid? Not automatically. The first step is identifying what is actually missing, because a dulled throat sensation is a property of the base rather than of the concentration. Many people restore their reference point by changing the form of nicotine or the flavour instead. ### Which ratio gives the best flavour? Propylene-heavy liquids give sharper, more defined flavour because that base carries aroma compounds more cleanly. Glycerine-heavy liquids round flavours out and make them more enveloping. Neither is better, and the coil in your device narrows the choice anyway. ### What happens when a nicotine shot and a shortfill have different ratios? The finished liquid lands somewhere between the two, weighted by volume. A 50/50 shot in a 70/30 shortfill nudges the result towards propylene glycol, which is usually slight but enough to move the throat sensation, and it appears on neither label. ### How do I know which ratio my device accepts? Coil documentation normally states a suitable range. Two practical signs confirm it: leaking points towards needing a thicker liquid, while a dry or burnt taste points towards needing a thinner one that can reach the wick. ## Read the ratio before suspecting the figure One reflex prevents most of the trial and error in this subject: when the sensation changes, look at what changed on the label before questioning the concentration. The base is the thing that moves most often without anyone noticing, especially when the flavour or the device has just changed. The same nicotine figure does not produce the same experience depending on what carries it. Propylene glycol sharpens, glycerine envelops, and both behaviours combine with whatever power your hardware runs at. Reading the **PG/VG** ratio alongside the concentration means you stop correcting a number for a problem that never came from it. That, page after page, is the most reliable way to understand what you are actually feeling. Editorial content for adult readers only. Nicotine is a highly addictive substance. Not for sale to anyone under 18 in the United Kingdom. Nothing here is a purchasing recommendation or a recommended nicotine strength.