Antibiotics are frequently used to treat moderate to severe acne that is not responsive to other treatments. Some, like tetracycline, are commonly prescribed. Others, like amoxycillin, less so. But in all cases, antibiotics are used to help decrease the number of bacteria that become trapped in and around hair, hair follicles, and sebaceous glands.
Aside from taming breakouts, antibiotics can help limit consequences like permanent scarring, which occurs in about 20% of all people living with severe acne. While effective, these drugs have side effects that should be considered.
This article details the antibiotics commonly used to treat acne and how they work. It presents information about side effects, as well as the growing problem of antibiotic resistance that may affect how and when they’re prescribed.
How Antibiotics Work on Acne
Antibiotics work by several mechanisms. The most important one is the decrease in the number of acne-related bacteria in and around the hair follicle.
Specifically, the follicle becomes obstructed and an overgrowth of normal skin bacteria destroys the lining of the follicle. As a result, the bacteria and debris enter the dermis layer of the skin, causing an inflammatory response.
Antibiotics also work by reducing the irritating chemicals produced by white blood cells. Finally, antibiotics reduce the concentration of free fatty acids in the sebum, also reducing the inflammatory response.
How Long Does It Take For Antibiotics to Clear Acne?
Generally speaking, expect to use antibiotics for three to four months before you notice significant acne improvement. The recommended course will, however, differ depending on the medication used and your skin.
Some people may take an antibiotic for much longer, with one study of amoxicillin reporting an average duration of 37 weeks. Your dermatologist will ensure they’re prescribing safe and effective treatment.
Tetracycline
Tetracycline was once the most widely prescribed class of antibiotic for acne, but it’s the tetracycline derivatives like doxycycline and minocycline that are more commonly used today.
It’s important to complete the full course of any antibiotic treatment prescribed for acne. Don’t expect immediate results.
There are several antibiotics within the entire class, including tetracycline, which remains available in both 500-milligram (mg) and 250-mg formulations.
The usual starting dose is 500 mg twice a day continued until a significant decrease in acne lesions is seen. The dose can then be decreased to 250 mg twice a day or discontinued.
Tetracycline may cause stomach upset. Eating it with non-dairy foods is often advised, as dairy products decrease absorbtion and render it less effective.
Tetracycline should not be given to people who are pregnant or children under 9 years of age.
Minocycline
Minocin (minocycline) is a tetracycline derivative that has been used effectively for decades as a treatment for acne. It is especially useful for pustular type acne. A pustule is a pus-containing vesicle such as a whitehead surrounded by redness.
While the absorption of minocycline is decreased with food, it is not as significant as the decrease seen with tetracycline. The usual starting dose is 50 to 100 mg twice a day.
Minocycline (and theoretically any tetracycline derivative) should be avoided in those who are using Accutane (isotretinoin) as the combination of these may result in a condition in which there is increased pressure within the skull (pseudotumor cerebri).
Major side effects of minocycline include dizziness, nausea, vomiting, skin pigmentation changes, and tooth discoloration. The skin and tooth changes are seen more often in people who have taken minocycline for a long time.
Doxycycline
Doxycycline is often used for people who do not respond to or cannot tolerate erythromycin or tetracycline, or for those who will likely have difficulty with the “no food” guidelines of some drugs.
The dosage of doxycycline is started at 50 mg to 100 mg twice a day. It should be taken with food; otherwise, it can cause significant nausea.
Doxycycline is more likely than tetracycline to increase sensitivity to the sun or cause sunburns, a phenomenon known as photosensitivity. There are other acne medications that may cause photosensitivity as well, such as benzoyl peroxide, alpha-hydroxy acids, and topical retinoids.
Doxycycline is available under these brand names: Doryx, Oracea, Monodox, Atridox, Morgidox, Vibra-Tabs, Alodox, Ocudox, Doxy, Acticlate, and Vibramycin.
Amoxicillin
Amoxicillin is not considered a first-line drug for treating acne. However, a study of 26 people who were first treated with other antibiotics without success found that 85% of them saw improvement with amoxicillin when used alongside topical treatments and/or hormone therapy.
Click Play to Learn More About Doxycycline Acne Treatments
This video has been medically reviewed by Casey Gallagher, MD.
Amoxicillin for acne has certain advantages. High among them is that it is safe for use in pregnant people. It can be used when drugs in the tetracycline class aren’t an option.
It typically has fewer side effects, though nausea, diarrhea, and headache can occur.
Amoxicillin for acne also may be a good option for people with allergies to doxycycline and other first-line drugs. A daily dose of 1000 mg, or in more serious cases 1500 mg, appears to work well.
In the United States, amoxicillin is sold under brand names including:
- AmoxicotAmoxilDisperMoxMoxilinTrimox
However, because it’s in the penicillin class of antibiotics, it can’t be used in people with penicillin allergies or, in some cases, those diagnosed with certain health conditions. Tell your healthcare provider about these conditions, which include:
- Kidney diseaseAsthmaHay feverMononucleosis
Septra/Bactrim and Macrolides
Septra or Bactrim (sulfamethoxazole/trimethoprim) and Zithromax (azithromycin) a macrolide, have often been used to treat moderate to severe inflammatory acne.
Studies do not seem to favor one antibiotic over another with this condition, but treatment appears to work much better when combined with topical therapy.
Topical Antibiotics
Clindamycin is most widely prescribed as a topical antibiotic. The starting dose is 75 to 150 mg twice a day.
Allergic reactions (sulfa allergy) are fairly common with sulfanomides, and significant resistance has been seen with both of these categories of antibiotics.
The major side effect of oral clindamycin therapy (which is rarely used anymore) is a serious intestinal infection called pseudomembranous colitis caused by the bacteria, Clostridioides difficile (C. difficile or C. diff).
A C. difficile infection is much more common with oral clindamycin but has been reported with the topical product as well.
Topical clindamycin is available as Cleocin-T, Clinda-Derm, Clindagel, Clindets, C/T/S, and Evoclin.
Antibiotic Side Effects
All antibiotics can cause vaginal yeast infections. Tetracycline seems to be the antibiotic that most frequently has this side effect.
All oral antibiotics can also lessen the effectiveness of birth control pills, so those who are taking these antibiotics should use a backup birth control method. Nausea is fairly common with erythromycin and doxycycline.
Concerns About Antibiotic Resistance
In recent years, healthcare professionals have been seeing increasing resistance of the bacteria Propionibacterium acnes against the oral antibiotics used.
It’s important to talk to your dermatologist about any potential side effects and when you should call with any symptoms.
Current strategies to reduce resistance recommend using antibiotics in combination with topical treatments and limiting the duration of use when possible. This, however, has impacted the overall effect of antibiotics on acne.
As is the case with prescribing any medication, the risks have to be weighed against the rewards. Discuss all of your options with your healthcare provider.
While short-term use of antibiotics is generally considered best, not finishing a recommended course of one of these drugs can actually contribute to the problem of antibiotic resistance.
A Word From Verywell
Antibiotics can be very helpful for some people with acne and work by a combination of mechanisms. Some antibiotics work better for particular types of acne and your dermatologist can make the best choice by understanding your history of acne as well as your lifestyle.
As with any medications, side effects may occur. Fortunately, there are several different choices available if one of the above is not helpful. Antibiotics are usually used in combination with topical treatments and good daily skin care for acne-prone skin.
Frequently Asked Questions
- Which antibiotic is best for acne?
- The most effective and safe antibiotic treatment for acne depends on the case and the type of acne. Doxycycline remains among the most commonly prescribed antibiotics for acne, along with minocycline and sarecycline.
- Learn More:
- What to Know About Minocin (Minocycline)
- Can amoxicillin worsen acne?
- Some topical antibiotics can lead to symptoms associated with skin purging, such as dry and flaky skin. This is when acne appears worse for up to a few weeks because of an interruption of the skin cell-replacement process. Systemic antibiotic like amoxicillin are less likely to cause this, however.
- Learn More:
- What Are Skin Pigmentation Disorders?
The most effective and safe antibiotic treatment for acne depends on the case and the type of acne. Doxycycline remains among the most commonly prescribed antibiotics for acne, along with minocycline and sarecycline.
Some topical antibiotics can lead to symptoms associated with skin purging, such as dry and flaky skin. This is when acne appears worse for up to a few weeks because of an interruption of the skin cell-replacement process. Systemic antibiotic like amoxicillin are less likely to cause this, however.
