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. note
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. note
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! Only... not, in reality. Although taking a placebo when you should be taking actual treatment might.
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. If the person prescribing the placebo knows it's fake, it may be a Motivational Lie. Compare All-Natural Snake Oil and Spice Rack Panacea for "natural" remedies that often prove to be placebos. It can be considered a form of Self-Fulfilling Prophecy. When this works on Applied Phlebotinum, it's (naturally enough) the Placebotinum Effect. Compare Fake High for when this happens with intoxicants.
- 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 does some Leaning on the Fourth Wall, 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 Rurouni Kenshin, when Kenshin was a child training with his master Hiko Seijuro XIII, Hiko fed him what he claimed was a miracle medicine to help him recover from a snake bite. Years later, when Kenshin heavily injures Hiko while completing his training, Kenshin feeds him the "medicine". When he recovers, he explains that the "medicine" was just water and herbs.
- Asterix: In Asterix in Britain, despite the heroes best effords, they fail to bring any magic potion to Anticlimax's village. Asterix then gets the idea to brew a potion from the herbs Getafix gave him - he doesn't know if they'll be magical, but it might encourage the village's warriors. Sure enough, the placebo effect works, the Romans are defeated, and Mykingdomforanos decides to make the concoction the national drink. The name of the plant? Tea.
- 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: Albert'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.
- In 50 First Dates, Adam Sandler's character starts out seducing women by getting them drunk on fruit beverages they only think are alcoholic.
- After Cain is wounded in a battle and loses most of his right hand in the Ciaphas Cain series, he notes a few times that the cybernetic replacement fingers give him a steadier grip on his pistol as they don't tremble as much when he aims. His editor comments in a footnote that the trembling of a shooter's hand is mostly caused by their own heartbeat, and thus cybernetic fingers wouldn't affect it at all - but if he feels more confident in his aim, so much the better.
- In It:
- It is revealed that Eddie Kaspbrak's asthma is psychosomatic, and his medication is a placebo.
- Interestingly, since the power of belief is what actually harms IT, Eddie's placebo "asthma spray" harms IT and drives IT back. Even though Eddie knew by this point that the medicine was a placebo, he still subconsciously believed that it could keep harm away from him, and so the spray repelled IT.
- Captain Underpants thinks his powers are neutralized if he's sprayed with spray starch. So Harold and George hastily draw up a new origin story comic claiming he swallowed a powerful artifact with the ability to neutralize spray starch. George almost mentions it by name, calling it the "placenta effect".
- In the Discworld books, this is usually how witches help people; they do something mundane but make people think that powerful magic is being used. In one example, Granny Weatherwax is taking care of someone with a bad back, and while he's distracted figuring out how to use her potion, she cracks his back into alignment with her foot. (The witches have also done the sinister version, like the one who discovered a thief had stolen from her and did nothing but give him some very knowing looks; he ended up so frightened of her he ran away to sea.)
- Footprints on the Ceiling: Madame Rappourt invokes this trope when Linda Skelton begs her to let her try some of the medium's "trance capsules". Because Rappourt doesn't know if the morphine and scopolamine combo she takes is safe for Linda, she hands over sugar-filled capsules instead. note
- 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 M*A*S*H they run out of morphine so they give the patients, many with compound fractures, sugar pills telling them it's a strong painkiller. The ploy works (though helped with ice packs and sleeping pills).
- A B-plot from another episode has the MASH experiencing a heat wave that makes 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. 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.)
- There's a nocebo when they're testing "Driving Angry"; part of Kari's plan to get Grant and Tori really angry before they drive is to give them "laxatives", also actually vitamin pills, which she tells them about afterwards. The fake laxatives weren't enough to make them actually have a Potty Emergency, but being worried about them added to the stress they were feeling.
- In the It's Always Sunny in Philadelphia episode "Flowers For Charlie," dim-witted Charlie is given a drug by scientists to boost his intelligence. Charlie is soon shown speaking Mandarin, working on equations and romancing women. At a big presentation, Charlie announces his massive breakthrough: allowing cats and spiders to talk to each other. The scientists then reveal there is no drug, the experiment was to see what would happen if someone thought they were now a genius. Charlie demands to know how he can speak Mandarin only to have the Chinese scientist state that Charlie has just been spouting gibberish and he's pretended to understand it. The gang actually point out how stupid an experiment this is as they storm out.
- In Ninja Turtles: 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 & Teller: 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.
- ER has an episode when this was intended to be done without the patient's consent. A doctor examines a patient finds nothing wrong but the child and her parents are worried, so the doctor orders the intern to get a bottle of "Obecalp" for the patient. The intern is confused and walks off the their big book of medicines and cannot find it. When a Dr. Weaver, a higher rank than the previous doctor, hears what the intern is looking for, she angrily explains the implications and goes to the first doctor. She chews him out for this stunt because if it goes south, they could be sued for negligence and tricking the patients with their medicine, to say nothing of just public backlash.
- Houdini & Doyle: Faith healings turn out to be caused by this, as many people claim is really the case.
- On NCIS: New Orleans, Sebastian is panicked being on a boat so Tammy gives him some "Chinese herbs" to calm him down. Sebastian is able to take down an attacker and thinks the herbs must have given him a boost. He rants on more side effects so Tammy tells him that all she gave him was some cold medication. Sebastian thus realizes he really did take that guy down on his own.
Patton: You got placeboed, man!
- Blake's 7. The Cult Colony on the penal planet Cygnus Alpha requires everyone to take a medicine for the rest of their lives, to fight off a disease that infects anyone who lands on the planet. Turns out the disease is only a mild infection that the body quickly adapts to, and the 'drug' is just a placebo the cult leader uses to maintain control over the potentially unruly prisoners.
- 7 Yüz: The hypnotic "treatment" Oşa gives Pınar in "Hayatın Musikisi" is nothing but a placebo it only makes her feel confident and empowered because she believes it does.
Oşa: You hear it because you believe that you do. There is no song. I only made you believe that it would cure you.
- Discussed in one episode of Sabrina the Teenage Witch, where Sabrina is having a disagreement with her aunts, and the Witch Council shows her two alternate futures, one where she lives with Hilda, one where she lives with Zelda. In Zelda's future, Sabrina is scientifically-focused and dispensing an anti-aging treatment to Alpha Bitch Libby (after making her beg for it, which Sabrina enjoys). Then Mr. Kraft walks in with comically exaggerated wrinkles and says "Be honest, I'm getting the placebo, aren't I?" To which future Sabrina admits he might be in "group C," which is actually receiving an aging potion.
- 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.
- In Final Fantasy VII, Cloud doesn't get motion sickness until he sorts out his memories enough to remember that he always gets motion sickness - although a Dummied Out scene reveals that he's cool with it, as a trade-off for being who he really is. (He also doesn't get sick if he's driving or 'nervous'.)
- Up + B and tapping B to increase the odds of success of a thrown Pokeball in Pokémon. It has been proven both by Word of God and by fans themselves analyzing the various game's coding and capture rate formulas that neither of these have any effect on the Random Number God. Fans don't care; to this day many fans do these "tricks" and swear that they make capturing Pokemon easier.
- Ape, Not Monkey regularly expresses the opinion that alternative medicines, if they appear to work at all, are just placebos.
- Schlock Mercenary: There's this gem during an enemy False Flag Operation:*
Murtaugh: Kathtryn, be brilliant. Tell me what the enemy has planned in order to prevent live capture.
Kathryn: I'm already working on that. I just need a little quiet.
Sorlie: You can order people to be brilliant?
Murtaugh: Shh... as long as they think I can, I get pretty good results.
- 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.
- Spoofed several times in xkcd:
- In this strip the narrator confesses that he trolls scientific studies by secretly giving LSD to the control group, "which, at one point, led to a study showing that LSD produces no more hallucinations than a placebo."
- This strip points out that while the placebo effect works well with things such as pills, it's a little harder to apply to scientific studies of, say, sexual activity.
- This strip demonstrates the Logic Bomb that results from trying to apply The Scientific Method to a study of the placebo effect: how can you run a valid experiment if you have to use placebos to make a control group? note
- In one Good Mythical Morning video, Rhett and the rest of the Good Mythical Morning crew played a prank on Link by telling him that they would be testing out a new pill purported to reduce the spicy taste of food. In reality, these pills were fake and Rhett ate food that only looked spicy to be able to act like the pills were working for him while Link had to eat actually-spicy food. However, Link was fooled into believing that the pills really were helping reduce the spiciness he tasted from his food even when he ate a ghost pepper, one of the hottest peppers in the world.
- 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. She eventually tries to reverse it by going back to the seller, who admits 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.
- King of the Hill had an episode where Dale thought the military had subjected Bill to experiments that made him gain weight, meaning they're responsible for his life going downhill. However, later on Dale mentions that the drug was named "Place-bo", which makes Hank realize that there was no drug and Bill's poor health was his own fault.
- 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 its "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. (In the words of the 1023 Campaign, "Homeopathy: There's Nothing In It".)
- Homeopathy "works" in accordance to The Laws of Magic (specifically, law of similarity and law of contagion). So, maybe not in our reality...
- Iridology, claiming to diagnose disease and injury by looking closely at the iris of the eye. 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. Also, Your Mind Makes It Real - anxiety and loneliness can make you ache, and feeling looked after may help. And if you're willing to pay a quack money to look after you, the quack is more than willing to take it.
- Guess why the pharmaceutical industry spends more money on advertising than research.
- This actually plays a role in genuine scientific research, since clinical trials for drugs usually involve a double-blind study, in which half of the participants are given placebos to serve as a control group. For a drug to be approved, it has to perform demonstrably better than the placebo, as presumably a drug (or even surgical procedure) that works no better than a placebo is itself a placebo.
- Better trials are ones that compare the new drug against the one currently considered the best to treat the condition; Doctors would generally much prefer to know that a drug is at least as good as the current, usually cheaper alternative than to know it's better than no treatment at all.
- Some public utilities, such as street-crossing signs, elevators, and thermostats, include buttons that don't actually function. The so-called placebo button serves not to operate the machinery but to keep people contented by giving them the illusion of control. For example, when office workers can't change the temperature in the room, they're likely to become disgruntled and upset if they feel too hot or cold; if they believe they can change the temperature, that belief is enough to calm them down. And similarly to the placebo effect in medicine, pressing a "lower temperature" button on a thermostat that you think works can be enough to make you actually feel cooler.
- Must Have Caffeine is this trope zigzagged. Caffeine can keep you awake... Just not in the doses the average person takes. Studies demonstrated that eating an apple was more effective for staying awake than drinking a cup of coffee... Up the intake of caffeine enough, though, and it will keep you awake.
- Apparently, some people think gluten is so evil they feel bad after ingesting a nocebo (i.e. food they were told contains gluten, while it really doesn't), even though they are not actually gluten intolerant. Your Mind Makes It Real - but still, never self-diagnose. Doctors exist for a reason.
- The infamous ad campaign for HeadOn loudly exhorted the viewer, "Apply directly to forehead!" Allegedly a headache cure, the product's active ingredients were... inert wax. It would do just as much good to rub a candle on your face. The manufacturers cleverly used Exact Words to avoid making any claims for false advertising; notice they didn't technically say the product would, well, cure headaches.