"I'm coming down the stairs and I find a large box. I recognized this box because I had been forced to purchase it. And at the time, I bought the largest one I could possibly find, so that I wouldn't have to go through that again any time soon. In fact, if they had a silo full of those suckers, I would have dragged that home behind the truck. Big pink silo: Always."
Alice just started her period and has run out of tampons. She is busy so she nonchalantly asks Bob, her boyfriend, to get them for her. Bob just stares in horror. Alice explains that she can't go, but she needs them as soon as possible so he would have to get them. Bob freaks out as he embarks on the most horrifying journey to the store that he will EVER have to face: the Tampon Run.
Played for Laughs, this trope exemplifies just how much of a big deal men stereotypically make out of menstruation. For whatever reason, this naturally occurring event and the purchasing of products to aid the process is this most terrifying thing in the world for any individual with a Y chromosome. He may be seen talking to himself, shouting to nobody in particular upon finding out that "they come in sizes?!?!?!", and trying to hide it. Men might try to play it off by asking if they come in larger sizes. Bonus points if he sees another guy in the same boat or if the sales clerk calls for a price check effectively announcing to the whole store that Bob is buying tampons.
Compare to Wacky Cravings where it is also often exaggerated by the husbands or if the writers are guys and to All Periods Are PMS where the poor unfortunate guy is being sent on the errand because every 28 days his loving mate turns into an evil conniving bitch. Contrast No Periods, Period.
A Dr. Pepper commercial, set to I Will Do Anything For Love, had this among a montage of embarrassing things the guy would do for his girlfriend. For the curious: The "But I won't do that" part was sharing the soda with her.
Ubykotex lampshaded this in a recent commercial found here where men would rather watch her bike than buy her tampons.
Inverted in the pro wrestling fanfic, "Tampax Pearl", when Stacy Keibler has to buy tampons and hilarity ensues when they have to do a price check. Further inverted as John Cena is the one who comes up and tells them the correct price.
In The Proposal with Sandra Bullock and Ryan Reynolds, Bullock says a line something like "If you don't go along with this, everything you've been through, all those late-night tampax runs, will have been for nothing."
This happens in the French movie L'Enquête Corse, in which one of the insurgents needs a tampon to make a fuse. So he goes in the pharmacy, blushes and stutters his way to asking the counter girl for a box of tampons, then she asks if he needs regular or super-absorbing. Of course he's made even more nervous and finally lets out that it's for a slow-burning fuse, at which point she tells him which one to use. (This being the Theme Park Version of Corsica, where dropping non-fatal bombs for independence is a daily occurrence and can identify, by sound alone, where a bomb went off, how much and what kind of explosive was used.)
In Miss Congeniality 2, to lose the three FBI agents escorting her back to Quantico, Gracie faked a sudden period and ran off to the toilet with Sam. The three remaining agents were tasked with getting the tampons.
In this unforgettable scene from Ten Inch Hero, Priestly (played by Jensen Ackles) has to do so in a kilt, mohawk, and eyeshadow. When confronted by other guys, he's a little embarassed at first, but then recovers quite nicely and proceeds to turn the situation on them.
The scene in Jack & Sarah where Jack has to buy some sort of lactation-related product (either nipple pads or nipple shields) for his pregnant wife is similar in spirit.
Man Of The House does this with dignity and with making it a plot point, as the romantic interest helps our hero out.
There's a joke where a new salesman for a store that sells everything manages to sell a fishing rod, a boat, and a car that was big enough to carry it to one person over the course of a single day. When his boss asks him how he managed to pull this off, the salesman replies: "He came in to buy some tampons for his wife. I told him 'Your weekend's shot, you may as well go fishing.'"
In the period-themed anthology Don't Cramp My Style, the one story contributed by a male author was "The Heroic Quest of Douglas McGawain", by David Lubar, in which—you guessed it—the title character buys tampons for his girlfriend. The female cashier is impressed, saying "it takes a real man to buy tampons for a lady".
In the John Ringo novel Paladin of Shadows, Ringo's ex-SEAL protagonist explains to one of the female hostages he is rescuing that tampons make great field-expedient bandages because of their absorbency, and condoms can be used as waterproofing for underwater detonators. He relates the story of a time when his squad ran low on these supplies and had to go and buy them at a drugstore.
There's a young adult novel about a couple who run away to live in the wilderness after both their families suffer tragedies. The girl is shocked to find three boxes of tampons among the supplies her boyfriend had packed for their sojourn, amazed that he could bring himself to (or would even think to!) buy such a thing.
Live Action TV
Blossom did it to herself when she had to go buy tampons for the first time. She chickened out when she saw that a cute boy from school was the clerk.
Carly alludes to sending Spencer on one in "iDate a Bad Boy."
In American Restoration, Rick Dale sends his son on one when he finds himself restoring a Kotex vending machine.
In On The Fastrack, Wendy sent Art the first time their daughter needed them. This being a family comic, she didn't speak directly — and Art tried hard not to know what she meant.
Bill Engvall did a routine about getting pads for his daughter, since his wife couldn't get them that day. Of course Hilarity Ensued, because a) his son found them first, and b) tried to be helpful by hollering the entire length of the aisle to his dad that'd found them.
In the Web Original setting Paradise, humans are randomly, permanently Changed into Funny Animals (with some experiencing a gender-change at the same time), though this Change is Invisible to Normals who will continue to see the person as his or her old human self (and gender). Many newly male-to-female gender-Changed find themselves effectively doing Tampon Runs for themselves (before the masquerade breaks down, at least): while still apparently male, they must shop for feminine accessories and hygiene products.
In Jenni Smith's "The Jade Box," Gender Bender victim Stuart (now Amy) has her first period, and must visit the drugstore for pads (she draws the line at tampons). The saleslady calls for a price check.
King of the Hill, Hank is forced to do this for Connie, the next-door-neighbor girl because she gets her first period when her parents and his wife are away and she's staying at their house. Being Hank, he creates an organized detailed binder with everything a man needs to know about shopping for products in the "feminine aisle". When Connie's parents get home, he gives it to Kahn Sr. to help him deal with his daughter's new monthly cycle.
Alluded to/ subverted in another episode when Hank is about to go to the store and is aghast that Peggy included her "feminine items" on the list... which turns out to be diet soda.
As many men can tell you, this is quite common in Real Life.
Interestingly, it actually applies to girls as well, because a) there's usually a year or so in the beginning where other people knowing that you have a bodily function that literally half the rest of the planet also has is really embarrassing which makes buying your own pads/tampons torture until you get over yourself and realize that no one cares, and b) the many different products/brands/sizes etc. are confusing even if you're a girl, until you've become familiar enough with the whole thing that you just find one or a few products you feel comfortable with and stick with them forever.
Very awkward for FTM transgender people in Real Life, especially if passing is required before testosterone therapy and/or surgery, or if hormones and surgery are unavailable options.