Don't expect a luxury day-spa. A Prague beer spa is a quirky, touristy ritual where you sit in a wooden tub filled with warm beer, hops, and malt while the wort ferments around you. The smell is strong (malty, yeasty, like a brewery floor). Most places give you a mug of fresh beer on tap that you can refill while you soak for 20-30 minutes, followed by a quick wrap in a blanket and 20 minutes sweating on a bed of straw or in a salt room. It's fun for 45-60 minutes total. The “healing” claims are mostly marketing; it's really just a silly, relaxing novelty that smells like breakfast cereal and beer.
Go in winter (November-February) when the contrast between cold Prague streets and a warm beer tub feels genuinely rewarding. Summer works but feels less special. Expect to pay around €60-€110 per person depending on whether you choose a private tub for two or share with strangers. Couples usually book private rooms. One solid tip: always pick the private tub option if traveling with a partner; sharing a large communal tub with random tourists is awkward. Skip any add-on massages or “special” herbal packages; they're usually rushed and not worth the extra money. Book for late afternoon so you can wander the Christmas market or Old Town afterwards while pleasantly buzzed.