Articles, Blog

Why Shouldn’t You Take Medicine with Grapefruit Juice?

December 16, 2019


If you’re like me you probably tune out
pharmaceutical commercials when they air on TV. But there’s one drug warning that stands
out: “Don’t take this medication with grapefruit juice.” But what’s wrong with grapefruit juice?
And what’s in grapefruit juice that isn’t in other citrus juices, like orange juice,
the normal one? Grapefruit is full of a type of organic compound
called furanocoumarin, which interferes with the activity of an enzyme in your small intestine
called CYP3A4. Problem is, that interference means your body
will absorb more of certain medicines, for things like high cholesterol, high blood pressure,
and anxiety, than it’s supposed to. This enzyme’s normal job is to chemically
change certain potentially dangerous compounds before they can get to your bloodstream or
liver. That way, they’re easier for your body to eliminate. But it also recognizes lots of different medications,
and deactivates them the way it would any chemical — meaning that a large amount of
the drug you take never actually makes it into your body to do its job. Except that the compounds in grapefruit deactivate
the enzyme. Just one glass of grapefruit juice is enough to knock out nearly half of it. So, if the enzyme deactivates drugs, and the
compounds in grapefruit deactivate the enzyme, that sounds like a good thing. More effective
medications! No! It is not a good thing, because one of
the first things researchers do in a clinical trial is work out a safe dose, one that takes
into account your body’s attempts to remove toxins, including that enzyme. When your grapefruit juice gets rid of the
enzyme, you’re suddenly getting way more of the drug than that safe dose. That could cause serious problems for your
liver, which normally filters out these medications after they’ve done their job. You can also
have too much of the medication in you! If you drink a bunch of grapefruit juice while
you’re taking blood pressure medication, for example, your blood pressure could fall
too far. So if you take any meds but you’re a big
fan of grapefruit juice, you might want to talk to your doctor before you crack open
a new bottle. Or just switch to orange juice, which tastes much better anyway. Thanks for asking, and thanks especially to
all of our patrons on Patreon who keep these answers coming. If you’d like to submit
questions to be answered, or get these Quick Questions a few days before everyone else,
go to patreon.com/scishow. And don’t forget to go to youtube.com/scishow and subscribe!

53 Comments

  • Reply Canadian Geese Own Eagles All Day November 22, 2017 at 11:15 pm

    Unless you're taking opiates. Then grapefruit yourself to feel better.

  • Reply Rakad November 23, 2017 at 12:17 pm

    Pop half a xanny wih grapefruit juice

  • Reply Karis Coyne November 25, 2017 at 10:29 am

    The other fun thing about this is that mixing grapefruit juice and alcohol makes you like 10x drunker than you would ordinarily get.
    Source: Horrifying personal experience.

  • Reply interestingyoutubechannel November 29, 2017 at 9:29 pm

    What I learned from this is to add grapefruit zest when I roll a joint, and possibly a few drops in my coffee.

  • Reply Depressio Expressio November 30, 2017 at 4:29 am

    Weed and grapefruit ?

  • Reply Dead Inside November 30, 2017 at 10:15 pm

    does this mean if someone over dose u can just drink grapefruit juice?

  • Reply Yasser November 30, 2017 at 10:54 pm

    Who likes grapefruits anyway !

  • Reply Vinny C December 4, 2017 at 9:46 pm

    gonna drink a whole cup of grape juice when I next try any oral recreational
    drug

  • Reply rk kwc December 4, 2017 at 11:04 pm

    actually, my mom did this. I can't remember if it was orange juice or grapefruit juice but she drank some with some medicine while she was pregnant with my sister. She ended up hydropumping vomit everywhere.

    Not a good idea.

  • Reply superapple4ever December 7, 2017 at 2:47 am

    I wonder if this applies to grapefruit and Adderall.

  • Reply Ashmations •3• aka Ashley December 7, 2017 at 2:41 pm

    Drink grapefruit juice at a bar then you can't get druged

  • Reply Reid Skull December 8, 2017 at 12:48 pm

    Because grapefruit is disgusting

  • Reply Acme Fixer December 13, 2017 at 9:01 pm

    They ought to sell "decaffeinated" grapefruit juice!

  • Reply Jim The EDC Guy December 21, 2017 at 12:47 am

    All the opiate users know this trick lol.

  • Reply Phaux Redtail December 30, 2017 at 4:18 pm

    Also the same stuff, also known as bergamottin, is found in Earl Grey tea. Guess how I learned that x.x

  • Reply Dominique D January 6, 2018 at 1:31 am

    What about grapefruit seed extract in pill form?

  • Reply MWB Gaming January 7, 2018 at 5:15 pm

    i could see some people taking their meds with grapefruit juice and lowering the dosage to save money lmao

  • Reply Sierra White January 8, 2018 at 10:34 am

    If we can spend the money to do a federal study on female pig orgasms (and yes, they apparently do have them), we can figure out safe doses for people that like a glass of grapefruit juice in the morning. WE HAVE THE TECHNOLOGY!

  • Reply Dymon Beats January 26, 2018 at 10:30 pm

    This works with weed lol

  • Reply yuuue January 31, 2018 at 2:49 pm

    The shade against grape fruit juice lovers is real

  • Reply Newer Account January 31, 2018 at 6:03 pm

    My dr tells me to drink 3 glasses with my suboxone

  • Reply Travis March 6, 2018 at 2:24 pm

    So that's why there have grapefruits everywhere in "Fear and Loathing in Las Vegas", in the car, at the hotel… eheheh

  • Reply Frost Night March 16, 2018 at 9:08 pm

    Time to take 60mg Prozac and 60mg Adderall with a big ol' gallon of grapefruit juice
    Thanks for the tips Hank

  • Reply mannacler April 1, 2018 at 10:53 am

    I like grapefruit juice more than I like orange juice.

  • Reply Anomaly88man April 10, 2018 at 5:23 pm

    People say grapefruit juice intensifies dextromethorphan dissociation. So, that must be true for any enjoyable drugs like opiates stronger too!

  • Reply JAMES PURKS April 15, 2018 at 6:01 am

    That is really only half the answer. The other half is grapefruit juice also deactivates an enzyme in the liver which creates similar problems.

  • Reply Jascha Bull May 6, 2018 at 12:59 am

    Is it known why grapefruits have a particularly large amount of furanocoumarin inside them?

  • Reply Madison Sara June 29, 2018 at 7:37 am

    I'd bet $20 someone read that label and thought they could still eat grapefruit because you're not technically drinking it.

  • Reply Madison Sara June 29, 2018 at 7:37 am

    I would love an episode on why it's called grapefruit (and other misnomers), even though it's not made from grapes…

  • Reply pennypay1 July 6, 2018 at 8:21 am

    I was told about this when I went on MMT. Grapefruit juice would likely render my methadone dose too strong, and my body would use it up too quickly. The intention is for a dose to last 24 hours on average, because unlike insulin, you can't take additional methadone if you start to feel low (from withdrawal symptoms). The drug is extremely powerful, and you don't want to mess with potentiating the 'high', or take contraindicated drugs with it.

  • Reply Duck sauce August 3, 2018 at 9:44 pm

    Who drinks grapefruit juice?

  • Reply Nox August 13, 2018 at 7:24 pm

    Sooooo grapefruit and cocaine you got alot more bang for your money. Sweet thanks sience!

  • Reply Amonra Elias August 26, 2018 at 10:09 pm

    Wait this video was to short … Could you use this to get drunk ? Make your self a cheepr date ??? So to speak how or if it can how can this apply more then just meds

  • Reply Liam Watson September 12, 2018 at 5:43 pm

    Orange juice is safe but not Seville Oranges in marmalade.

  • Reply Slade Healy November 7, 2018 at 1:30 am

    DXM mixed with sunny delite #SESH #BONES

  • Reply Taniria York November 15, 2018 at 4:58 pm

    The way you talk is very nice to listen to sir

  • Reply patrapper7 November 22, 2018 at 5:48 am

    Now I will take my aspirin as well as grapefruit juice to get rid of a headache faster

  • Reply Filip laskovski December 26, 2018 at 4:36 am

    Whoopsy ?

  • Reply Laddie McGee January 20, 2019 at 9:14 pm

    If you take sprycal for CML don't drink grapefruit juice either.

  • Reply King Pin_55 January 28, 2019 at 4:11 pm

    I drank a whole big bottle of white grape fruit juice once for that exact reason

  • Reply carrythatweight January 31, 2019 at 5:08 pm

    Thank you I've always hated grapefruit but I'm about to get lit tonight

  • Reply Frank Andrew I February 23, 2019 at 7:13 am

    Pink grapefruit juice the best

  • Reply Radio cure June 27, 2019 at 12:10 pm

    I just drank a whole bottle of grapefruit cider without realising. . .

  • Reply aztekwarrior23 July 17, 2019 at 2:03 am

    So what if you take half the amount of medication recommended with a glass of grapefruit juice?!? Would this be just right?

  • Reply LennoxTheMenace July 17, 2019 at 6:25 pm

    Cough medicine like dextromethorphan helps dry cough but if you take more than the recommended dose it becomes a dissociative drug and if you take enough of it you can have an out of body experience while tripping. You can mix grapefruit juice with this and it infact gives more visuals, the visuals look like LSD visuals.

  • Reply Uriel238 August 28, 2019 at 6:42 am

    Nope. I like me my grapefruit juice. I also take atorvastatin. The best way to manage interactions like this (according to my doctor) is to space them out by at least two hours. I eat grapefruit in the morning and take my meds at bedtime.

  • Reply sdfkjgh August 29, 2019 at 12:07 am

    I prefer pomelo.

  • Reply Rhiannon Ruadh August 29, 2019 at 12:46 pm

    But can we use this method to reduce the required dose and bring down drug costs?

  • Reply jg pliskin September 4, 2019 at 7:55 pm

    You telling me I'll get higher if I take drugs with a shot of grapefruit juice?

  • Reply Blacky Chan October 15, 2019 at 6:51 pm

    Who's here for kratom and grapefruit juice?

  • Reply victor 91 October 29, 2019 at 9:42 pm

    Most deceptive "fruit" in the world

  • Reply thulomanchay November 18, 2019 at 2:20 am

    Don't take grapefruit juice with your medication.
    If you take your medication in the morning, you could have your grapefruit in the afternoon.

  • Reply Hail Satan December 12, 2019 at 7:58 pm

    10mg codeine + 1 litre grapefruit juice, I'm feeling something

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