Addiction glossary · Slang

Gurning & Coke Jaw

By Gary Clinton·Addiction specialist·Glossary

Gurning is the involuntary jaw-clenching, teeth-grinding and face-pulling that comes with cocaine, MDMA and other stimulants — the tight, chewing, can't-keep-your-mouth-still feeling, often without realising you're doing it. "Coke jaw" is the dull ache and stiffness the next day, from a night of it.

Why it happens

Stimulants put your whole nervous system into overdrive and crank up muscle tension. The jaw — one of the strongest, busiest muscle groups you've got — takes a lot of that load, so it clenches and grinds on its own.

Why it matters

Beyond looking out of it, repeated clenching genuinely wears down teeth and strains the jaw joint over time, and dry-grinding while numb does damage you won't feel until later. It's also an honest tell: the bigger the gurn, the bigger the dose — and usually the harder the crash coming.

What to do

The clenching eases as the drug wears off, and a one-off won't harm you. But if gurning and coke jaw are a regular feature of your nights, that's a marker of regular, heavy stimulant use — and worth an honest look. The cocaine guide and a quick self-check are good places to start.

Frequently asked questions

Why does cocaine make you gurn?

Because it overstimulates the nervous system and spikes muscle tension; the jaw clenches and grinds involuntarily as a result. The same mechanism causes it with MDMA and other stimulants.

Is coke jaw permanent?

The next-day ache passes, but repeated grinding can cause lasting damage to teeth and the jaw joint. Frequent coke jaw is a sign of frequent heavy use worth taking seriously.

Gary Clinton
Gary Clinton
Ireland's cocaine & addiction specialist — CBT-qualified, bestselling author of Never Give Up, and an ex-addict himself. Private one-to-one help for professionals, online and worldwide.

Recognising a bit too much of this?

If the tell-tale signs are becoming the norm, an honest conversation helps. Private, confidential, no lecture.

Book a confidential chat → Take the free self-assessment