What to Know Before Taking Cephalexin for Acne

cephalexin

 Getty Images/Design by Cristina Cianci

If you feel like you've tried everything to treat your acne (and we mean everything), you've probably started looking into alternative treatments instead. But since the usual acne-fighting favorites don't seem to do the trick, the chances of hydrogen peroxide or other DIY recipes that the internet favors working for you are pretty slim. It goes without saying that if you find yourself in this situation, a visit with a dermatologist to address the underlying cause and develop a treatment plan is a must. But while you're at your appointment, you might be lead to ask them about cephalexin, another alternative acne treatment. Not exactly one of the common acne-fighters we typically hear about, cephalexin is better known for treating infections in the body, but interestingly enough, it might be worth considering for acne. Below, board-certified dermatologists Nikhil Dhingra, MD, of Spring Street Dermatology in NYC; Jeanette Black, MD, of Skin Care and Laser Physicians of Beverly Hills; and Rebecca Baxt, MD, of BAXT CosMedical; as well as board-certified internal medicine specialist Ehsan Ali, MD, of Beverly Hills Primary Doctor, explain exactly what you need to know about taking cephalexin for acne purpose.

Cephalexin

Type of ingredient: Antibiotic

Main benefits: Typically used to treat a variety of bacterial infections, including bacterial skin infections and infected post-operative wounds.

Who should use it: According to Dhingra, cephalexin is occasionally used for acne flares for patients unable to tolerate tetra-, mino-, and doxycycline (the common antibiotics for moderate-to-severe inflammatory acne). Cephalexin also might be a good option for women planning to be pregnant or currently pregnant but experiencing moderate-to-severe acne flares and can't use traditional acne treatments. Black says the medication is usually well-tolerated, but it should be avoided in patients with allergies to cephalosporins.

How often can you use it: Cephalexin should be taken as advised by your doctor, but Baxt says for acne, it would likely be prescribed twice daily for two to four weeks. Black adds, "long-term antibiotic use can be avoided by using other, often more effective treatment modalities."

Works well with: Since very few oral medications are ideal as a monotherapy, Dhingra stresses the importance of continuing a topical regimen prescribed by your dermatologist.

Don't use with: Ali says when taking cephalexin, alcohol should be avoided; otherwise, there are no restrictions.

What Is Cephalexin?

According to Black, cephalexin (also known as Keflex) is an oral antibiotic typically used to treat a variety of bacterial infections, including bacterial skin infections. How does it work? Black says it's a first-generation cephalosporin that inhibits cell wall synthesis in certain bacteria. If cephalexin sounds familiar, that's because it's a commonly used antibiotic for various infections, such as skin infections, sore throat, and UTIs, according to Ali. "Cephalexin isn’t by any means a novel antibacterial agent," Dhingra explains. "It has been around for quite a while and is used by dermatologists for other common skin infections and concomitantly with skin surgeries to prevent common infections." 

There aren’t a ton of formal studies regarding the efficacy of cephalexin for treating acne, but Dhingra points to a 2008 analysis that looked at close to 100 patients treated with cephalexin. Eighty-four percent had tried and failed a different oral medication prior to a cephalexin trial, and the results showed nearly 75% of patients had improvement, with just over half experiencing significant improvement. However, Dhingra highlights that it wasn’t a formal study done comparing cephalexin to a placebo, which is the gold standard of scientific analysis. "Beyond that, the caveat that stands out most to me is that the average duration of treatment with cephalexin was 8.8 months, which is a lengthy duration to be on any type of antibiotic when safer longterm solutions exist, such as isotretinoin," notes Dhingra.

Benefits of Cephalexin for Acne

Using antibiotics to treat acne is nothing new. Because they can eliminate acne-causing bacteria and they also have an anti-inflammatory property, which helps prevent and treat acne, antibiotics are one of the main categories of internal treatments for acne. However, the oral antibiotics used for this purpose are typically minocycline and doxycycline. According to Dhingra, cephalexin isn’t actually able to penetrate into the oil glands like the more traditional antibiotic choices are able to. So then the question becomes: in what instances would someone use cephalexin over all the other acne treatments? A few to note below:

  • Those unable to tolerate other antibiotics: "The data is scarce, so it’s hard to offer a broad recommendation, but for a patient for whom doxycycline isn’t cutting it and patients are maybe hesitant about other highly effective tried-and-true acne treatment—like spironolactone and isotretinoin—cephalexin may be a reasonable thing to bring up with your dermatologist," Dhingra explains. It should also be noted that cephalexin should only be used for inflammatory acne (think the red angry bumps, cysts, and pustules).
  • Pregnant women: Since traditional acne treatments are not safe during pregnancy, Dhingra says cephalexin might be a good option for women planning a pregnancy or who are currently pregnant but experiencing moderate-to-severe acne flares. It's important to note that consideration for this approach should be done in conjunction with a board-certified dermatologist and obstetrician. 

Other Skin Benefits

  • Treats infections: According to Black, cephalexin is commonly prescribed for skin infections and infected post-operative wounds. "Given the growing risks of antibiotic resistance, prescribing cephalexin is typically reserved for active infections," Black explains. "Wound cultures can be taken to confirm a bacterial infection and test its sensitivity to antibiotics."

Side Effects of Cephalexin

According to Black, the antibiotic is usually well-tolerated, but it should be avoided in patients with allergies to cephalosporins. Baxt adds that there can be cross-reactivity to cephalosporins and sometimes penicillin, so anyone who is allergic to those should reconsider using cephalexin as a treatment.

Adds Ali, the risks or side effects of using an antibiotic, such as cephalexin, include allergic reactions, rash, nausea, and diarrhea. But perhaps the most concerning side effect of using an antibiotic to treat acne is antibiotic resistance and therefore definitely a reason to approach with some caution. "Propionobacterium acnes, the bacterium responsible for acne flares, has exhibited a large rise in antibiotic resistance over the past few decades with use of antibiotics, in general," Dhingra explains. The other concern is that prolonged cephalexin courses can introduce the risk of resistance for other bugs like Staph bacteria, making treatment of other conditions with cephalexin more difficult, he notes.

To sum it up: before taking cephalexin, make sure you are not allergic to it, be aware of the potential side effects, and notify your doctor of any unusual reactions.

How to Use It

If you miss a dose, Ali advises taking it when you remember and never doubling up on it.

Dhingra says if the decision is made between you and your doctor to go down this route, it’s very important to continue a topical regimen prescribed by your dermatologist as very few oral medications are as ideal as a monotherapy.

TL;DR: "For someone who has struggled longterm with acne, despite the best attempts at treatment with the standard fare of treatment options like doxycycline or minocycline, cephalexin might be a good option to try if you have inflammatory acne," Dhingra says. "This should be done in conjunction with a board-certified dermatologist comfortable with the gamut of acne treatments available."

Up next: Should you take amoxicillin for acne?

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