Not tea at all, botanically
“Herbal tea” is a catch-all for infusions made from herbs, flowers or fruit, like chamomile and peppermint, rather than from Camellia sinensis, the plant that produces black, green, white and oolong tea. USDA’s figure for herbal tea brewed from a bag is 0 mg of caffeine per 8 fl oz cup, because there’s no actual tea leaf involved.
That makes it a genuine zero, unlike decaf black tea, which still carries a couple of milligrams because it starts from real tea leaves and removes most, not all, of the caffeine.
Check the blend
The catch is that “herbal tea” isn’t a protected term, and some blends marketed that way include real tea leaves, yerba mate, or guayusa, all of which do contain caffeine. A “herbal chai” or a fruit blend cut with black tea will carry real caffeine despite the herbal branding. Reading the ingredient list is the only reliable check; if actual tea, mate or guayusa is listed, the drink is not caffeine-free.
Why it matters
For anyone avoiding caffeine entirely, whether for pregnancy, a sensitivity, or an evening cutoff, a genuine single-herb infusion like chamomile or peppermint is one of the few drinks that adds nothing to the day’s total. It is also a safe late-night alternative to black tea (47 mg an 8 oz cup) or green tea (about 29 mg), given caffeine’s mean half-life of roughly five hours (NCBI), which keeps real tea circulating well into the evening if drunk after dinner.