It’s the one product the celebrity image consultant Amanda Sanders recommends to all her clients.  It’s not a new diet pill, injection or $1,000 face cream.  It’s dry shampoo — a way to wash your hair without setting foot in the shower.

Sanders, who has been using dry shampoo herself for about 10 years, finds it’s great for getting ready in a pinch or making a good salon styling last longer.

“I shot a movie in Prague and I had my husband bring a suitcase of it. That’s how much of a fan I am,” said Sanders of New York City, who has dressed celebrities including Chris Rock and Wanda Sykes.

What once seemed to be a forgotten fad from the 1970s is back in a big way, first creeping its way into the toolkits of hairstylists at fashion shows, then nudging its way into high-end hair product lines and, finally, finding its way onto drug store shelves.

Dry shampoo devotees say the spray-on cleanser streamlines their mornings, letting them put off the ordeal of hair washing.  And high-maintenance types love it as well.  Those who consider hours before the mirror time well-spent use it almost like make-up for the hair to give their locks a fuller look.

But as some may learn the hard way, dry shampoo must be applied with caution.  Misuse can lead to awkward moments.

Dry shampoo, a minor 1970s fad, has gone mainstream. (Photo by Bek Andersen)

For those still stuck on traditional lathering, here’s the scoop on dry shampoo:  It comes in spray-on varieties and shake-on powders.  Some brands market themselves as time savers, others as environmentally conscious water savers (in a not so earth-friendly aerosol can) and still others as a way to make unwashed hair smell clean.

Most come out white, but others come in colors to match the hair, thus avoiding the powdered-wig effect.  What they all have in common is an absorbent ingredient, sometimes made from minerals, other times from grain ranging from corn to rice. You spray it on, let it sit, then comb it out, removing oil and odor in the process.  And as an added bonus, any residue makes your hair look thicker.

Dry shampoo used to be hard to find. In 2000, there were only about five brands in the United States to choose from, according to Mintel Americas, a market research firm.  Bit by bit, high-end hair care lines such as Bumble and Bumble and Frederic Fekkai released their own versions, the most expensive ones going for about $35 a bottle.  Now, there are more than 70 options, at least 40 coming out in the last three years alone.  In 2010, the value brand TresSemmé released a dry shampoo for about $5. Suave followed this year with a $3 one.

Dry shampoo is flying off the shelves, said Dominick Costello, co-owner of Ricky’s NYC, a beauty supply chain that has carried it for more than 20 years.  In 2006, the store had about three dry shampoos.  Now, there are about a dozen.

“It’s gone over the top,” said Costello, 45.  “It’s just crazy.”

As word of water-free washing spreads, busy people are finding relief.  Mornings got easier last year for Michelle Pickoski, a 23-year-old nursing assistant and student in Bucksport, Maine. That’s when a British girl moved to town, introducing Pickoski and her best friend to the mysterious powder.  Pickoski’s hooked.  Some mornings she can skip the shower, just spraying her hair once to freshen it up.

“Now I don’t have to worry about getting up that half-hour early before heading into work or school,” said Pickoski.  “It’s just a quick spray and you’re good to go.”

Fans of dry shampoo include high-maintenance types as well.

Mirna Gonzalez works with wigs, so good hair is never far from her mind.  When she washes her own tresses, it takes about 40 minutes to go through the ritual of blow-drying and flat-ironing her hair, using various sprays and serums along the way.  Dry shampoo helps her make all that work last another day or two.

But even when she lathers up in the shower, she still reaches for two different brands of dry shampoo after.  She uses a white version all over her head and follows up with a more expensive black one to cover any white residue, particularly at the crown.

“I use it to create volume — to create that volume from youth,” said Gonzalez, 28, of Ann Arbor, Mich.

Even though the colored dry shampoos can blend into dark hair, they aren’t without their pitfalls.  Ryan Jacobson of San Jose, Calif., has been using dry shampoo for three years, and he knows this all too well.

“One day my boss once said, ‘Ryan, your bronzer is dripping,’ and it was a little sprinkle from my dry shampoo,” said Jacobson, 25, a coffee shop employee and student.  “I was like, ‘Dammit! I’ll wipe it off but just so you know that’s not bronzer — it’s my dry shampoo.’”

Now Jacobson applies dry shampoo only when he’s in a bathrobe, and he double-checks for any flakes or smudges before leaving the house.

But the popularity of dry shampoo is no excuse to skip the soap.

“I hope people are still showering,” said Costello of Ricky’s NYC and laughed.

Email: as2523@columbia.edu