Does pre-shave oil actually do anything, or is it just gunking up my brush and making the razor slide about?

Got given a bottle of pre-shave oil for my birthday and I've been dutifully using it for a fortnight. I can't honestly tell if it's doing anything. The shave feels about the same. What I CAN tell is that my brush now feels greasy, the lather seems thinner than it used to be, and the razor head is collecting a sort of film I have to scrub off.

So a few things. Is the oil supposed to go on before or after the hot water? How much is "a few drops", because the bottle says nothing and I've been using maybe six or seven? Does it actually protect the skin or is it just a nice smell? And is the greasy brush thing normal or am I using too much?

Not trying to be a cynic, I'd like it to work. But right now it seems to be making my lather worse for no obvious gain.

Six or seven drops is a lot. I use two, maybe three, rubbed into a wet face right before I lather. The film on the razor and the greasy brush are exactly what too much looks like.

Whether it does anything is a fair question. For me it helps on the neck in winter and I can't tell the difference in summer, so I don't bother in summer.

Experiment I did last year because I had the same doubt: one week with, one week without, everything else identical. Verdict: slightly less tug on the first pass on the jaw, no difference anywhere else, and it made zero difference to razor burn, which I'd been hoping it would fix. The thing that actually fixed my burn was lightening my pressure and a fresh blade, not the oil.

So it's a nice to have. It's not the thing standing between you and a good shave, and if your lather has got worse since you started using it, that's a net loss.

Graham, straight answer: pre-shave oil does something, but it's a small something, and at six or seven drops you're paying for it twice, once in the bottle and once in the lather. Two to three drops on a wet face, worked in for a few seconds, and you should barely see it. If the brush feels greasy or the razor is gathering a film, you're using two or three times what the job needs.

What it actually does is add a thin layer of slip between skin and blade and hold a bit of moisture in the beard while you lather over it. That's the whole mechanism. It doesn't soften the beard (warm water does that), it doesn't replace the lather (the lather is the cushion and the protection), and it won't fix razor burn caused by pressure or a dull blade, which is what slantcurious found. Where it earns its place is on the first pass over the neck and jaw, particularly in cold weather when skin is tight and dry. On a face that's well hydrated and under a good lather it's often not noticeable at all, and that's not a failure, it's just the lather doing the job already.

Order: wash the face, warm water or shower to soften the beard, then the oil on wet skin, then lather straight over it. Oil on a dry face beads and does nothing useful. And your thinner lather is real: oil in excess coats the bristles and interferes with the soap, so rinse the brush thoroughly after each shave and the problem clears within a few uses once you cut the dose. I've covered the oil and cream versions and where each fits in pre-shave and aftershave explained, and if the lather itself has gone off, the loading and water side is in how to build a lather.

Usual caveat: if your skin stings or breaks out with a particular oil, that's the product not suiting you rather than technique, and a pharmacist can tell you more about the ingredient than a forum can.

Late to this but for what it's worth: I gave up on the bottle and found a smear of ordinary unscented moisturiser on the neck before lathering does the same job for me, and my brush stopped smelling like a chip pan.

Update. Two drops instead of seven, on a wet face straight after the shower, and rinsing the brush properly. Lather's back to normal after about four shaves and the razor film has gone.

Can I tell the oil's doing anything? On the jaw, a bit, on the first pass. Cheeks, no. I'll finish the bottle at this rate some time in 2028 and probably won't buy another, but I've stopped resenting it.