Placebo Effect

Armand: What are you giving him? Drugs? What the hell are "Pirin" tablets?!
Agador: It's aspirin with the "a" and the "s" scraped off.
Armand: (beat) My God, what a brilliant idea.

The placebo effect is where a patient thinks that a 'medicine' is healing them, even though it doesn't have an actual medical effect. The most common use is in drug trials, in which a control group is given a placebo, to compare the effects in case the drug actually is only effective due to the placebo effect, or is even worse.

One difference between fiction and reality is that, unlike in fiction, real placebos often continue to have an effect even if the user finds out it's a placebo - the action of taking the "drug" is usually enough to fool the body.

The opposite is the nocebo effect, in which someone believes something is hurting them or making them sick, when it's really not. This could even kill them, as Your Mind Makes It Real.

See Magic Feather in terms of the plot. A more realistic version of Clap Your Hands If You Believe. Related to Brand Names Are Better.


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    Anime and Manga 
  • One chapter of Sayonara, Zetsubou-Sensei has a field day with this trope, including Nozomu taking a placebo drug and breaking out in hives from the percieved side effects, Stalker with a Crush Matoi forcing Nozomu to take a fake Love Pill, only for the effect to work on her instead when she's the only one convinced that it worked, and Nozomu eventually getting fake surgery performed on him to get rid of the fake side effects from the fake drug he took at the start, and ending up convinced that he's been turned into an android.
    • The chapter also throws some Leaning on the Fourth Wall into the mix, by introducing a sticker that, if you stick it to a manga, makes it six times funnier. Immediately the sticker starts showing up more and more, until the last two pages are covered in them.

  • In Eurotrip, two of the characters order brownies at an Amsterdam bakery run by a Dreadlock Rasta. They immediately become stoned beyond belief...until the Dreadlock Rasta calmly informs them that they're not hash brownies.
  • The protagonist of Matchstick Men, who has severe OCD, is given a packet of pills by his psychiatrist that apparently heals him. Around the same time, he starts bonding with his long-lost daughter. He eventually learns that the pills are just soy menopause supplements, and that bonding with his daughter has given his life meaning and helped him overcome his neurosis.
  • The Birdcage: Armand's "Pirin tablets" — he seems to think they're some kind of powerful anti-anxiety medication; they are in fact Aspirin with two letters scraped off. They seem to do the job, though.
  • In Space Jam, the Tune Squad has completely given up hope of winning their basketball game against the Monstars until Bugs Bunny gives them 'Michael's Secret Stuff', which buffs them up and gives them the confidence to get back in the game. Of course, the real secret is that it is just water.
  • Subverted in The Exorcist. In one scene, a priest douses the demon-posessed protagonist with tap water and claims that it's holy water, but the protagonist screams in pain anyway. Later, though, it's implied that the demon only pretended to be fooled so that the priests would think that the "possession" was purely psychological and wouldn't try to exorcise it. When the priests douse the protagonist with real holy water in the climactic exorcism scene, the screams are real and the water leaves visible burns.
  • An inadvertent psychotherapy version appears in What About Bob?: Bob's new therapist gives him a copy of his book Baby Steps, which is about setting small, attainable goals. Bob completely misses the point and thinks that he has to physically take small steps wherever he goes. However, Bob's focus on taking "baby steps" when he gets nervous helps distract him from his fears and allows him to do things he wasn't able to do before.


    Live Action TV 
  • Star Trek: The Original Series At the end of Mudd's Women.
  • The Red Green Show had an episode where the lodge members were part of a test-market for an energy bar, making them very active and becoming addicted. When the test batch ran out, they reverted back to normal, only for Harold to reveal all they got was a basic granola bar to gauge product interest, due to the real stuff being too dangerous. Red, taking this as proof of the strength of his mind, salvages one of the test sample bars and tells his wife at home to wait up that night.
  • In an episode of Frasier, Niles eats a normal brownie thinking it's a pot brownie, with the reverse situation for Martin. Hilarity Ensues.
  • One time on Mash they run out of morphine so they give the patients sugar pills telling them it's a strong painkiller. It works.
    • On the B-plot of that episode, they're experiencing a heat wave that has everyone miserable. They give Klinger some of the sugar pills claiming they're some sort of new drug that will allow him to feel cooler. He spends the rest of the episode in his regular uniform while everyone else is wearing undershirts.
  • The Suite Life on Deck: Bailey uses a placebo to raise London's intelligence. Subverted in that after realizing that it's a placebo, London returns to normal. Then she takes another placebo.
  • On The Big Bang Theory, Raj is unable to talk to women unless he's drunk. In "The Terminator Decoupling," the guys are on a train when they discover that Summer Glau is in the same car, and they all try to hit on her. Raj drinks copious amounts of beer before going over to talk with her, and she actually seems to like him. Then Howard walks over and informs him that it was non-alcoholic beer. He clams up and walks away without another word.
  • Referred to when the MythBusters tested seasickness cures. To be certain that Adam and Grant weren't subconsciously skewing the test results, Jamie gave each of them an "over-the-counter medicine" that was actually a vitamin pill. (Grant fell for the placebo, but Adam got sick just as fast as in the other tests.)
  • In The Next Mutation, the Turtles have a recurring team of foes that once used a magic formula to enhance their abilities. The effect ended when the turtles pointed out the 'magic' was just a placebo.
  • Used when NewsRadio parodied Flowers for Algernon. Joe makes Matthew a "Smart Drink", which works until Matthew gets smart enough to realise it's only working because he thinks it will.
    Matthew: It's like when Wile E Coyote runs off a cliff. He can stay standing in mid-air until he looks down.
  • Penn And Tellers Bullshit episode "Yoga, Tantric Sex, Etc." featured a man trying to explain why herbs work for some people and not for others. Penn summed up the entire argument in one sentence.
    Penn: If you believe they work they work, if you don't they don't. You hardly ever hear that about penicillin.
  • UK comedy show Smack the Pony has this in one sketch, with a rather inept and lazy doctor. When her patient points out that saying she's going to give her a placebo will negate the effect, she attempts to evade embarrassment by writing down a made-up drug name on the prescription.

    Video Games 
  • Metal Gear:
    • In Metal Gear Solid 2, Snake can find muscle relaxant drugs on the Tanker. Calling up Otacon to find out their function leads to him explaining that they eliminate hand shakes with sniper rifles... but that there doesn't appear to be any sniper rifles there, so Snake might try them if he's feeling seasick. Taking them causes the nauseating up-down motion of the in-game camera to gently lessen and then stop. If Snake then calls up Otacon, he reports that his seasickness is gone, to which Otacon amusedly replies that the drug doesn't do that and he's experiencing the placebo effect.
    • In Metal Gear Solid 3, if Snake finds Russian Glowcaps, he is convinced they will recharge the batteries on his equipment. His radio contacts assure him that this is stupid. If you try eating them anyway, the batteries do charge, and reporting back to Para-Medic causes Sigint to suggest the placebo effect as an explanation (since neither of them have a better one). After agreeing that it is, and that it could be really useful, they both assure him that 'of course eating glowing mushrooms will recharge your batteries' in a very patronising tone.

    Web Comics 
  • Ape Not Monkey regularly expresses the opinion that alternative medicines, if they appear to work at all, are just placebos.
  • Once in S.S.D.D Norman fell asleep before his eyes could even close after taking some random pills that Kingston claimed were sleeping pills, but were really just aspirin. And apparently Anne once conned another hour of sex out of Richard with some sugar pills.

    Western Animation 
  • Dogbert has a placebo that works even when the user knows it's a placebo.
    • That, and the people he's giving them to are usually too stupid to realize what a placebo is.
  • The Simpsons: The Crazy Cat Lady once regained her sanity thanks to a medication but lost it when she learned it was a placebo.
  • In the Handy Manny segment "Fearless Rusty", Lovable Coward Rusty is sprinkled with "magic dust" by a local magician, who claimed it would make him brave... and he believes it.
  • In one episode of Hey Arnold!, Helga bought an anti-love potion that successfully killed her feelings for Arnold only to learn later on that it was just grape juice.
  • In the My Little Pony: Friendship Is Magic episode "Leap of Faith", the Flim Flam brothers start hawking a new cure-all miracle tonic that helps Granny Smith start feeling better. Then Applejack finds out that it's just apple juice with beet leaves added, and the rest of the episode revolves around her trying to figure out if she should tell everyone the treatment is a fake, or keep it under wraps so Granny keeps feeling good. She eventually decides to bust them because they vastly overstate the curative properties (up to implying that it can fix broken limbs), causing Granny to attempt to high-dive. A placebo might help her feel better, but it's not actually curing anything.

    Real Life 
  • Chiropractic adjustments are controversial, owing to the fact that there's little scientific proof that the person doing an adjustment (technically a Doctor of Chiropractic, since they aren't actually medical doctors) is doing anything other than basic decompression of the spine. But because these 'doctors' are very good at convincing people they'll feel better, they do tend to feel better.
  • Acupuncture also has very little proof that it is effective (yes, they are able to do studies with needles that look like they are inserted, but actually are not), but people really believe that it helps them.
  • Therapeutic Touch therapy and it's "Eastern" equivalent, reiki, worked through this effect as well - it's so easily debunked that a 9-year old girl was able to do it, as seen here.
  • Homeopathy may fool many people due to the placebo effect, despite the fact that it would have to utterly violate some of the most basic laws of physics and chemistry in order to work.
  • Iridology. In the words of The Other Wiki:
    Iris texture is a phenotypical feature which develops during gestation and remains unchanged after birth.
  • Pretty much all pseudoscientific "treatments" depend on this. They are mostly (not entirely, but mostly) directed toward the relief of (chronic) pain, which is one of the most incredibly subjective things on the planet to attempt to measure.
  • Guess why the pharmaceutical industry spends more money on advertising than research.