All-in-one shampoo cleans your hair. It conditions. It’s often body wash. But some see it as a shortcut for the misinformed — apathy and convenience placed in one plastic bottle.

While women are marketed 12-step skin-care routines, Irish Spring offers men one green bottle with the instructions: “Pour it on your head and let gravity do the work.” The shampoo is a running gag. It’s not just a product, it’s a personality trait.

Some are infused with caffeine or protein. Others promise thicker hair or an arctic rush. These jack-of-all-trades products offer a whimsical, one-step solution to clean these dead strands of protein cells on your head, but can a single bottle really do the job well?

The answer is complicated.

The shorter your hair, the more likely you’ll find all-in-one shampoos perfectly fine to use, according to four cosmetic research and development experts we spoke with. Shampoo removes oil and dirt, cleaning your hair, but conditioner is intended to make your hair feel smoother and manageable. Shorter hair requires less conditioning, and standard all-in-one shampoos do deliver a portion of the benefits you’ll find in a normal conditioner, said Marisa Plescia, a cosmetic chemist with Bell International Laboratories in Minneapolis.

The longer hair grows, the more wear and tear it gets because of sheer exposure to the elements over time. Plus, there’s everything we humans do to our hair: We press it between two scalding plates, we curl it around hot iron sticks, we strip hair of its color and use a chemical reaction to create a brand new one.

“Mother Nature could have never figured out all the things that we do to hair in the name of beauty,” said Trefor Evans, the director of research at a nonprofit organization called TRI Princeton, which tests hair-care products for cosmetic companies.

Think of the surface of your hair like the tiled roof of a house, Evans said. Over time, tiles chip and crack. Conditioner manages the damage, smoothing over the tiles (known as cuticles). You’ll leave a wash with hair that feels soft and easy to comb. New conditioner formulas are actually given a “combability” test.

“For guys who don’t have particularly long hair, a little bit of conditioning is nice,” Evans said. “They don’t really need a full-blown conditioner treatment. You can probably get away with using the two-in-one.”

But what about someone with long, thick, curly hair? “Not even close,” Evans said.

All scalps have different needs, Plescia said. You should base your decision on how a shampoo or conditioner makes your hair feel after a wash.

“If you look in the mirror after you get ready for the day and think, ‘Oh, my hair looks good,’ it’s working for you,” Plescia said.

All-in-one shampoos hit retail shelves in the mid-1980s. Back then, the products simply added conditioning ingredients (no caffeine or arctic blasts). Randall Wickett, an emeritus professor at the University of Cincinnati College of Pharmacy, worked on some of the first products for Procter & Gamble. The modern all-in-one products will work for a lot of people, Wickett said.

“The formulations have evolved and improved a lot,” Wickett said. “A lot of companies have been working on this very hard for 35 years or so.”

It hasn’t been until the past 15 years that major brands — Axe, Dove and Suave — have created entire lines of men’s hair and body products, Evans said. Up until then,men tended to use whatever their wife or mother bought. Now, with entire shelves dedicated to men’s personal care in mass retail stores, all-in-one shampoos promising to save guys time in the shower have become some form of a meme.

Can you use body wash as a shampoo? Technically, yes. Body wash and shampoo both contain surfactants — albeit probably different types — and surfactants are what remove dirt from your hair and skin.

Science aside, the joke points squarely at the stereotypical, apathetic straight man who buys one bottle because, well, then he doesn’t have to buy two. It’s practical math compliments of American ingenuity. It’s one less bottle on the corner of your bathtub.

Behind the jokes on Twitter and Reddit, there’s often a biting commentary about the “pink tax” or the gendered expectations society places on beauty. Min Cheng, 23, a staffer on Capitol Hill, says all-in-one shampoos represent the bare minimum men can get away with in hair-care products compared with the dozens of products for women.

These bottles sell a “false dream of efficiency,” Cheng said, symbolizing the lack of effort expected or required for men in today’s world.

“It says to me that you don’t really know what you’re using and you’ve never put any thought into picking it,” Cheng said.

Jacqui Davis, a hairstylist and part owner of a salon in downtown Washington, said all-in-one shampoos are designed for “convenience and ease,” not hair care. Davis said that men who use only shampoo — or body wash — to clean their hair often come in to the PR at Partners salon complaining of dry scalps.

“Men come in, they say their hair is unruly but they’ve been shampooing and not conditioning,” Davis said, adding that more men have been asking her for recommendations regarding proper hair-care routines. “That’s something more and more men are becoming aware of.”

Steven Deleon, 21, an automotive technician in Roscoe, Ill., said he prefers using two separate products for shampoo and conditioner. For him, it’s like finding the right product to clean the leather seats in a car; you’d rather use wipesmade for that material than all-purpose cleaners that will get the job done on any material. It’s the same, from his perspective, for shampoo and conditioner.

“I feel the difference, but, you know, others might not,” Deleon said. “It doesn’t really matter if it’s men’s or women’s for me. Whatever works for my skin and my hair.”

There are few products a consumer interacts with more intimately than a shampoo, Wickett said. What you buy largely depends on one question: How does this pearlescent dollop of goo make you feel?

“You can make the best product in the world, performance-wise, and if it doesn’t smell and feel right, nobody is going to buy it more than once,” Wickett said with a laugh. “That’s the way it goes.”