Careprost contains the same active ingredient as Latisse. Photo:

Cheaper, generic drug alternatives to Latisse are beginning to pop up all over the internet, offering all the benefits of the pricey lash-growth drug at just a fraction of the price.

The problem is, they may not be safe, or even legal.

For those unfamiliar with the lash-lengthening obsession du jour, Latisse's lash-growing eye drops are the first FDA-approved drug to grow and thicken lashes. They sprung from the glaucoma treatment Lumigen after patients noticed that their lashes grew dramatically during treatment, and hit the market about a year ago.

But at around $120 for a 30 day supply and with a prescription required, the much-praised miracle worker remains out of the financial reach of many women looking to get a Betty Boop lash fix.

So, naturally, they seek alternatives. The lash-hungry gather online, on the message boards of Makeup Alley and Real Self trading tips about where to buy the latest off-label versions, and reporting back on how they're working. There are also popular Youtube videos of women documenting their personal fringe fests.

One drug that's rapidly gaining attention is Careprost, a generic version of Latisse that contains bimatoprost -- the substance originally used to treat glaucoma that's now the active ingredient in Latisse -- in an identical .03% potency. United Pharmacies touts the drug as "the same as Latisse," on their e-commerce website, claiming it "increases the length, thickness and color of eyelashes." The company also advertises it to treat glaucoma.

Careprost costs just $20 on the United Pharmacies website.

Yet dermatologist Dr. Tina Alster, Director of the Washington Institute of Dermatologic Laser Surgery, warns consumers to never make assumptions based on just one ingredient found in a product.

"It looks like the same thing, but it may not be. There's more to ophthalmic solutions than the active ingredient. As such, I don't advise anyone using a product that is not specifically FDA-approved - particularly around the eyes - regardless of cost savings," says Dr. Alster.

Meanwhile, opthamologist Dr. Jeffrey Whitman of the Key-Whitman Eye Center in Dallas, Texas, says that buying off-label bimatoprost online isn't as benign as it sounds, and should be approached with caution.

"There is no generic bimatoprost available in the United States. Marketers of Careprost are from other countries and buying these drugs is illegal in the U.S. However, Lumigan .03% is the same medicine as Latisse, but with an indication for the treatment of glaucoma. A patient would need to see their eye doctor to see if this would be ok for their particular eyes and to decide how and how much to apply since no applicator is supplied, if their doctor would agree to prescribe it," says Dr. Whitman.

Women on Makeup Alley and other consumer review sites have also been trading off-label usage experiences with Lumigan, which is made by Latisse-maker Allergan, but costs less at about $80 per 2.5 ml bottle, compared to the $120 for Latisse's 3 ml dropper.

But some users have experienced some unexpected side effects.

Latisse promises longer lashes in 28 days. Photo: Getty Images

"I noticed a couple hairs on the inner corner of my eye that I thought were just some small eyelashes that fell on my face. But as I tried to brush them away, I noticed that they were growing out of the skin by the corner of my inner eye. I can only assume that even though I used it on the skin by my upper lashline, some of the product got into my eye. Now, I am not a fan of chemicals in my eye and rogue hairs growing on my face, so I will not use this product again. If it works for you and you have no side effects, that is great for you. But in realilty, I was putting a medicine that was used to treat glaucoma by my eye, and I am just not comfortable doing that in the name of getting better eyelashes," says a reviewer under the handle of pawnshop_rose.

While Latisse comes with mini disposable brushes to apply the product with, women using the other drops say they're applying with anything from q-tips to eyeliner brushes, which causes some experts to question sanitary conditions and the amount of product that ends up in the eye.

Any drug with the active ingredient bimatoprost carries the risk of darkening the skin, a reaction that is temporary and reversible, as well as darkening eye color, which is permanent and irreversible. By applying the off-label products in varying ways that haven't been tested for safety, consumers could be spilling and sloshing too much of the drug in the eye area, increasing the risk of adverse side effects.

Attempts to enter the lash-growth market without adhering to FDA-approved pathways isn't new, as the company Jan Marini found with their product Age Intervention Lash. The lash growth solution was formulated with bimatoprost, yet was never approved by the FDA, even though it contained a drug ingredient. The agency raided the brand's stockhouse, forcing it to shut down production of the product.

And it was actually the aftermath of an eye product crisis that caused the FDA to form in the first place.

"Few know that the FDA was born in 1938 in response to the uproar over the severe allergic reactions in many users of Lash Lure, a cosmetic eyelash dye. There was even one case each of death and blindness. A congressional debate over the need for new and strong food and drug laws had been waging for the previous five years, and this was the straw that broke the camel's back," explains New York opthamologist Dr. Margeurite McDonald, clinical professor of opthalmology at New York University Langone Medical Center. "So in 1938, the new Food, Drug and Cosmetic Act was passed, and Lash Lure was the first product seized under its authority."

Speaking of the off-label use of eye drops containing lash-growth ingredients, Dr. McDonald adds, "This formulation of bimatoprost has not undergone the rigors of a clinical trial and FDA approval, which include not only large scale safety and effectiveness clinical trials, but investigations into the history of the drug vehicle and formulation, as well as very intense scrutiny regarding manufacturing processes. I would advise women to use only the FDA-approved product, Latisse."

If you don't want to dive into the cost and commitment of Latisse, yet feel skittish about using the emerging off-label uses of other drugs, there are holistic options available.

Products like RapidLash and L'Oréal Concentrated Lash Boosting Serum don't contain drugs like bimatoprost, and are instead formulated with a blend of hair conditioners and nutrients that stimulate and enhance natural hair growth. Priced anywhere from about $25-$50, these products are a fraction of the cost of their professional drug counterparts.

Users often report a perceptible change in lash growth and length after several weeks of consistent nightly use, though the results don't typically rival that of Latisse.

But for those looking to find a happy and safe solution to eyelash envy, it could be the best option of all.