Doxycycline is a synthetic derivative of the antibiotic tetracycline. It is marketed in generic preparations as well as branded generics with different commercial names such as Periostat and Adoxa. It is more affordable and, regrettably, less effective than its more popular cousin, minocycline. Doxycycline is effective in checking the development and spread of bacteria that promotes acne.

Doxycycline is an oral medication marketed in the form of tablets, capsules, syrups and suspensions. Each dose of doxycycline should be taken with a full glass of water. If you experience stomach discomfort after taking the medication, then take it with a full meal.

Besides being cheaper than minocycline, doxycycline does not bring about the harmful side effects associated with the more expensive minocycline such as vertigo, dizziness, and skin pigmentation.

The amount of doxycycline absorbed in your system is barely affected by your food intake, so you can take it with your meals. For mild acne, the medication is taken once or twice a day for one to two weeks. For medium to severe acne infections, the oral dosage of doxycycline is 200 mg at the start of treatment – or 100 mg every 12 hours. In the following days, dosage will be lowered to 100 mg single daily dose or 50 mg twice daily.

No drug is perfect. Even the most basic drug of humankind, the aspirin doesn't work every time for headaches. This applies to oral antibiotics that are used for acne treatments.

Doxycycline is fairly well-tolerated by most users. The widely reported side effects are diarrhea, abdominal discomfort, and nausea. Doxycycline belongs to the tetracycline group and, as such, can bring about teeth discoloration if administered to children below eight years old. As a rule, children below 8 years of age should not be given doxycycline.

Doxycycline's primary disadvantage, however, is it can cause severe sunburn after only a short period of sun exposure which is the worst side effect recorded in tetracyclines. While this is a rare occurrence, sun exposure should be minimized if you are taking this medication.

Tetracyclines such as doxycycline, when taken by pregnant women, can have harmful effects on the bone and teeth development in the fetus. Likewise, when a breastfeeding mother is taking doxycycline medication, the antibiotic can be passed to the infant through the breast milk. It is advised that you should first inform your doctor if you are pregnant or breastfeeding before undergoing doxycycline medication.

Doxycycline administered in very low doses (subantimicrobial doses) is currently being considered as an acne treatment. Small doses as low as 20 mg twice daily have demonstrated anti-inflammatory results without affecting P. acnes, the bacteria that promote acne growth. This path is taken to inhibit the gradual build up of bacterial resistance.

Tests on subantimicrobial doxycycline doses have so far been conducted on rosacea, an acne-like skin disorder that does not involve P. acnes, and there has been a marked decrease in sizes in the lumpy protuberances and papules of rosacea. Whether it will effectively treat acne without inhibiting P. acnes still remains a question.