Tampon Run

"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."

—Jeff Dunham

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 the period. For whatever reason, this naturally occurring event and the purchasing of products to ease the process is this most terrifying thing in the world for individuals with the Y chromosome. They 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 Menstrual Menace where the poor unfortunate guy is being sent on the errand because his female counterpart is an evil conniving bitch. Contrast No Periods, Period.

Examples of Tampon Run include:

Advertising

Averted brilliantly in this commercial for Libra Tampons.
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.

Fan Works

A fancomic by Black Lillian on Deviant ART depicts members of Organization XIII at the supermarket and demonstrates this trope quite nicely with a little spin to include condoms as well.
This fanfic for Teen Titans forces Slade, of all people, to go through one. Hilarity Ensues. Spoilers for Season 2.
A Fullmetal Alchemist fanfic has Ed go pick up tampons for Winry.

Comic Books

Thugboy had to do this for Empowered.

Film

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'enqueteCorse, 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.
Ten-Inch Hero shows us that the only thing worse than being sent out to get your partner's tampons is doing so in a kilt, mohawk, and eyeshadow. Made unforgettable in that the man wearing said kilt, mohawk, and eyeshadow is Jensen Ackles.

Literature

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.

Music Videos

In the video for "You're All I Need" by Method Man, a girl sends her boyfriend out to buy her tampons, before her mother starts screaming at her for getting involved with the guy in the first place. At the end of the video, her boyfriend brings them home, only for her to complain that he got the wrong ones.

Newspaper Comics

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.

Stand-Up Comedy

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.
Jeff Dunham provides the page quote.

Web Original

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.
From (The Customer is) Not Always Right: Why Cashiers Should Rule the World. Bonus points for how the cashier handles the poor guy's heckler.
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.
In this scene from Ten Inch Hero, Priestly at first humorously demonstrates this trope, but then recovers quite nicely when confronted by other guys.

Western Animation

South Park when Stan's sister made them go get her some tampons when they were trying to watch "Russell Crowe Fighting 'Round the World" in order to see the trailer for the new Terrence & Philip movie.
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.

Other

As many men can tell you, this is quite common in Real Life.
Very awkward for FTM transgendered people in Real Life, especially if passing is required before testosterone therapy and/or surgery, or if hormones and surgery are unavailable options.
It is often stated that this is just another bonus of getting a menstrual cup. It is true.
Marvin from the same-named strip in Mad Magazine, in an early strip.