A cup of tea is often thought of as the remedy to virtually anything that ails you. Feel a cold coming on? Have a tummy ache? Stressed out? Tea is pretty much always the answer. Surely tea can do no wrong, right? (Unless it’s one of those potentially sketchy detox teas.)

As someone who likes to sip something hot all day (hi, oolong tea), I have a mug of the beloved bev by my side, starting as soon as I finish my morning cup of coffee and lasting until I’m finished working in the late afternoon. A lot of my friends are all-day tea drinkers, too. Because tea is notoriously linked to so many health benefits (seriously, who does their PR?), it took me a long time to suspect that it actually might be to blame for a recurring headache I have almost every day around 4 p.m. Surely, it’s from my morning coffee or maybe I just need a snack, I thought. But after asking around, I’ve learned that tea headaches actually exist—and happen to a lot of people. Here’s why.

Why does tea give me a headache?

It’s simple: the caffeine in tea. “Tea can cause headaches mainly because of the presence of caffeine,” says Tania Elliott, MD. If you steadily drink a caffeinated tea for hours (such as black, yerba mate, or green), it can cause a headache for the same reason as drinking too much coffee can. Caffeine narrows the blood vessels surrounding the brain, and when you stop consuming it, they expand again, which can cause pain. That said, not all teas contain caffeine. However, other ingredients found in herbal teas may also cause headaches or other adverse reactions for some folks.

Common tea ingredients that may worsen headaches

Dr. Elliott says there are also some specific ingredients commonly used in teas that are linked to causing migraines. “Teas with ingredients such as ginkgo biloba, ginseng, and St. John’s wort have been shown in small studies to trigger or worsen migraines,” she says. “The reason is because these herbs can interfere with the metabolism of certain migraine medicines making them less effective.” In other words, if you popped an over-the-counter to help cure your headache, and brewed yourself a hot cup of tea with one of the aforementioned herbs thinking that will help, can actually backfire instead.

What are symptoms of tea intolerance?

Aside from headaches, some teas can also trigger intolerances or allergies, although rare. According to holistic health coach, herbalist, and Supernatural founder Rachelle Robinett, some herbs can cause a histamine reaction (aka an inflammatory response triggered by an allergen) in the body, which can in turn cause a headache, itchiness, or flushing. (And in more serious cases, anaphylaxis.) “A histamine reaction is a natural and necessary reaction [from your immune system], but when overly severe or chronically triggered, can cause rashes or headaches, and especially migraines,” Robinett says.

But this doesn’t mean you need to go cold turkey on the hot tea. “The approach for remedying that is usually to reduce high-histamine foods, including herbs [teas with citrus flavors in particular are considered high-histamine], but it’s important to consider what a ‘normal’ histamine reaction for most people is over-active for you. If your gut health is compromised, for example, that could cause a reaction since gut health and an immune response are directly linked,” Robinett says. Her advice to getting to the root issue is tracking when you’re headaches are occurring and if they are coinciding with anything else, like consuming high-histamine foods.

Can tannins in tea cause migraines?

What do tea and wine have in common? Tannins, aka polyphenols and what gives wine its bitterness and lip-puckering astringency. Although tannins are typically associated with positive health outcomes, such as its anticancer properties, some studies analyzing the consumption of red wine suggest that the naturally-occurring compound can potentially trigger headaches and migraines for others. That’s to say, it’s possible that the tannins in tea may also have a similar effect. Although, more research is needed on the topic to conclusively say.

Remember: how long you leave a tea bag in can also play a role in its strength and the amount of tannins that make it into your mug. “You will certainly extract more benefits the longer you steep a tea. You’ll get more flavonoids, polyphenols, and catechins, but you’ll also extract more caffeine and tannins, which can lead to a more bitter, unpalatable liquid the longer the leaves remain,” award-winning tea blender, Steve Schwartz, author of Art of Tea: A Journey of Ritual, Discovery, and Impact, previously shared with Well+Good.

The sweet (tea) spot for brewing? Investing in high-quality, loose leaf teas, and simply following the package instructions in terms of steep time and water temperature. After all, the pros behind the product have likely determined the most adequate guidelines for brewing the most delicious teas. And don’t forget to check if your tea has gone bad; because, yes, tea will spoil just like any other food in your kitchen.

A few telltale signs your tea is past its prime: It’s lost its potent, fragrant aroma, it’s flavorless, it’s oxidized, or it’s been infested by bugs (ew!). To prevent your tea from going bad, experts suggest storing tea in an airtight container kept in a cold, dark, dry spot in your home. Plus, keeping moisture at bay at all cost.

What types of teas should you drink?

Robinett says you shouldn’t give up on tea altogether. In fact, the herbalist says it’s still fine to drink tea throughout the day. Of course, it’s important to keep in mind that moderation is key and choosing one that’s not caffeinated and low-histamine (if these are headache-inducing triggers for you) will likely yield the best outcomes.

Some good options to consider that likely won’t give you a tea-induced headache: nettle, turmeric, chamomile, skullcap, and moringa, to name a few. You can also opt for some of the best teas for longevity, including green tea, herbal teas (made from rosemary, wild sage, and dandelion tea), or milk thistle tea, which contain a bevy of health benefits that promote healthy aging and are a common ritual for some of the longest-living people in the world. Ultimately, however, a little trial and error will likely help you determine the best tea for your lifestyle (and, hopefully, it won’t trigger a headache either).

When this advice is considered, it seems that the solution to a tea headache is, well, tea. (Just a different variety.) Hey, I’ll drink to that.

Watch the video below to see how green tea and matcha are different—and which one is healthiest: