As parents and allergy sufferers look for ways to avoid paying the high cost of prescription EpiPens, some folks are turning to homemade epinephrine-filled devices as a low-cost alternative. And who can blame them for trying? The manufacturer, Mylan, has inflated the price of EpiPens by more than 450 percent since 2007 — and is being investigated for Medicaid fraud as a result. But is the DIY approach a good idea when it comes to life-saving injections?

A bio-hacking collective called Four Thieves Vinegar has shown that you can make your own EpiPen — which they called the "EpiPencil" — for around $35. They've even posted instructions and a how-to video. However, the EpiPencil hasn't been tested or regulated, and experts advise against making your own. Why? Because when you make your own, you're in charge of measuring the correct dose of epinephrine. Do you want to be responsible for your loved one getting too much or too little medicine in a life-or-death situation? Or equally as scary: What if you're in the midst of a severe allergic reaction, and while you can't breathe or you're getting dizzy, you have to measure your own dose?

Why under-dosing and overdosing is dangerous

"When you’re having an allergic reaction, it’s a high-anxiety state, and your mental capacity can be compromised. You can be dizzy, light-headed or passing out," says Dr. Purvi Parikh, MD, an allergist in New York City and medical director for Allergy & Asthma Network. You’re not in the best state to inject yourself with a syringe full of epinephrine, she says. "Ideally, you'd want someone else with you who wasn't having an allergic reaction to draw it up for you, but you can never predict when or where you’ll be when you need it."

If the person having the reaction gets too little epinephrine, it's very dangerous, Parikh says. "With this type of reaction, epinephrine is the only medicine that saves lives. If you're not getting enough of it, it can result in you having a worse outcome. It can even be fatal. Timing is everything and dosing is everything," she says.

As for getting too much epinephrine, it's not as dangerous, Parikh says. "Epinephrine is short-acting and overall safe. But you are injecting yourself with adrenaline," she adds. This may be dangerous if you have a heart condition, for example. "Everyone is different in how they react to medications."

Food and Drug Administration spokeswoman Theresa Eisenman recommends against the use of homemade EpiPens. “It’s essential to remember that epinephrine auto-injectors are life-saving products, and it is critical that they are made to a high standard of quality so patients can rely on them to work safely and effectively,” she told The Parallax.

Why training is important

If you might have to use an EpiPen someday, you should be trained by a pharmacist or physician how to use it. And that's doubly true for homemade ones. "Most people don’t have experience in drawing up medications, and the dosing is very different than in other medications," Parikh says. "You want to make sure there are no air bubbles in the vial that can cause you harm. And how to inject it is important, too, because it should be injected into the muscle. You don’t want to inject it into a vein," she says.

If you opt for a homemade device, bring the vial and needle back to your doctor after you pick up the prescription to make sure you know how to use it correctly, Parikh says.

Why you shouldn't pre-fill needles

While Parikh admits that you could pre-fill syringes and carry them with you, she calls it a "recipe for disaster." While it does eliminate the need for measuring medicine during an emergency, she says there are just too many risks. First, epinephrine stored in a vial or needle loses its potency more quickly than when it's stored in an EpiPen. While EpiPens expire after one year, epinephrine in a vial lasts about three months, according to Consumer Reports.

"Epinephrine has to be stored in a certain way because sunlight and different factors degrade it," Parikh says. In prescription EpiPens, special filters block sunlight. And since you need to carry this medicine with you, it's not like you can lock it away in the dark to preserve it. "It’s hard to keep it protected all the time, and you wouldn’t want to inject medication that doesn’t have the correct potency," Parikh cautions.

Also, if you have young children with you, do you really want to carry loose syringes full of epinephrine around in a bag they're likely to access?

Angela Nelson ( @bostonangela ) is an exhausted mom of two young daughters and two old cats, and a Pulitzer Prize-winning digital editor with more than 15 years of experience delivering news and information to audiences worldwide.