Compare Doxycycline vs. Keflex

Head-to-head comparisons of medication uses, side effects, ratings, and more.

Vibramycin
(doxycycline)

Keflex
(cephalexin)

Treats bacterial infections. Vibramycin (Doxycycline) is good for treating many bacterial infections. It is also available as generic. However, it can make birth control pills less effective. You also have to protect yourself against sunburn.Treats bacterial infections. Keflex (cephalexin) is good for treating many bacterial infections, and is available as a generic.
Reviews & ratings
Filter group. All currently selected
Filter group. All currently selected
4.27Doxycycline
Reviews for Doxycycline
49%
of people (All ages) say Doxycycline is worth it
36%
say it works well
24%
say it's a big hassle
112 reviews
Have you used Vibramycin (doxycycline)?
Worth itNot sureNot worth it
Reviews for Keflex
64%
-15% worse vs. Doxycycline
48%
-12% worse vs. Doxycycline
14%
-10% worse vs. Doxycycline
686 reviews
Have you used Keflex (cephalexin)?
Worth itNot sureNot worth it
Side effects
DoxycyclineKeflex
  • Any adverse event 40%
  • Nausea 13%
  • Vomiting 8%
  • Diarrhea 3%
  • Bacterial vaginitis 3%
  • Headache 2%
  • Upper abdominal pain 2%
  • Vaginal yeast infection 2%
More Doxycycline side effects »

The Keflex FDA package insert doesn’t have numbers about how common side effects are.

More about Keflex side effects »
How it works
DoxycyclineKeflex
Vibramycin (Doxycycline) is a tetracycline antibiotic. It stops bacteria by preventing them from reproducing and repairing themselves.Keflex (cephalexin) is an antibiotic. It kills bacteria by preventing them from making their own protective covering.
Type of medication
DoxycyclineKeflex
Prescription onlyPrescription only
Available as
DoxycyclineKeflex
  • Pill
  • Delayed release capsule
  • Liquid
  • Pill
  • Liquid
Used for
DoxycyclineKeflex
Risk factors for serious side effects
DoxycyclineKeflex
  • Age 8 years or younger
  • Using oral birth control pills
  • Long antibiotic treatment period
  • Women of childbearing age
Detailed Vibramycin (doxycycline) risks & warnings »
  • Weakened immune system
  • Not taking Keflex (cephalexin) correctly
  • History of penicillin or cephalosporin allergies
Detailed Keflex (cephalexin) risks & warnings »
Pregnancy

Research studies with real people found harmful effects on unborn babies, but the benefits might outweigh the risks even if you’re pregnant. Talk with your doctor.

Research studies with animals haven’t found a risk to unborn babies, but it hasn’t been properly studied in humans.

Food
DoxycyclineKeflex
No food related info.
  • Can take with or without food.
  • Can be taken with or without food.
Upsides and benefits
DoxycyclineKeflex
  • Available in generic.
  • Available in different forms: tablet, capsule, and suspension.
  • Used to treat many types of bacterial infections.
  • Less resistance seen in bacteria to this antibiotic. Your doctor may run tests to see which antibiotics will kill the bacteria causing your infection.
  • Available in generic.
  • Available in different forms: tablet, capsule, and suspension.
  • Used to treat many types of bacterial infections.
  • Can be taken with or without food.
  • Generally few side effects compared with other antibiotics.
Downsides and risks
DoxycyclineKeflex
  • Can't be used in pregnant women and children under 8 years old.
  • Makes your skin more sensitive to the sun.
  • Has to be taken with plenty of water and food and you have to stay upright for 30 minutes afterwards to avoid stomach irritation.
  • Can make birth control less effective.
  • Can cause diarrhea.
  • Can cause diarrhea.
  • You may need to take Keflex (cephalexin) 2 to 4 times a day, which can be hard to remember.
  • If you're allergic to penicillins or other antibiotics, you might not be able to take this medicine.
Tips from our pharmacists for people taking the medication
DoxycyclineKeflex
  • Take the medication exactly how your doctor tells you to.
  • If you're using birth control pills, this medication can make them less effective.
  • Wear sunblock if you have to go out into the sun since your skin can become more sensitive to sunburn.
  • Can cause diarrhea, nausea or vomiting.
  • Space out any vitamins by at least two hours.
  • Take with plenty of food and liquids.
  • Don't take any medications with bismuth (Pepto-Bismol, Kaopectate) while taking this medication.
  • Don't lie down for at least 30 minutes after taking this medication.
  • Finish all of the medicine your doctor gives you, even if you start to feel better. Stopping it early can cause the bacteria to develop resistance.
  • Store the suspension in the refrigerator. Shake well before using, and discard the bottle after 14 days.
  • Can take with or without food.
Learn more
More about DoxycyclineSide effectsReviews & ratingsAlternativesFDA package insert
Have you used Vibramycin (doxycycline)?
Worth itNot sureNot worth it
More about KeflexSide effectsReviews & ratingsAlternativesFDA package insert
Have you used Keflex (cephalexin)?
Worth itNot sureNot worth it