Medically reviewed by Kristin Hall, FNP
Written by Our Editorial Team
Last updated 8/10/2022
Doxycycline is a popular prescription antibiotic. It’s used to treat a variety of conditions, ranging from acne to respiratory tract infections, eye infections, sexually transmitted diseases and many other bacterial infections.
If you’ve been prescribed doxycycline to treat acne, a bacterial infection or an STD, your healthcare provider may recommend either doxycycline monohydrate or doxycycline hyclate.
As antibiotics, both of these medications are equally effective. However, there are several small differences between doxycycline monohydrate and doxycycline hyclate that may make one drug more suitable for your needs and health than the other.
Below, we’ve explained these differences and provided more information on how both versions of doxycycline can help to treat acne, bacterial infections and other conditions.
Doxycycline is an antibiotic. Whether it’s sold in monohydrate or hyclate form, its effects in your body are largely the same. Doxycycline works by targeting and killing certain strains of bacteria, including those responsible for common bacterial infections.
As a treatment for acne, doxycycline works by targeting the bacteria propionibacterium acnes, or P. acnes. This type of bacteria can grow rapidly inside blocked hair follicles, leading to painful and inflamed acne lesions.
Like many other treatments, the results from doxycycline aren’t immediate. However, used over the course of several weeks or months, it can help to get rid of acne and treat a diverse range of other bacterial infections.
We’ve explained this process in more detail in our guide to doxycycline, while also listing common dosages, side effects, interactions and more.
Doxycycline monohydrate and hyclate both contain the active ingredient doxycycline, meaning they’ll both kill bacteria and treat bacteria-related conditions such as acne (and a wide range of other bacterial infections).
As antibiotics, doxycycline monohydrate and doxycycline hyclate are equally effective. Both are tetracycline antibiotics, both work in the same way to stop bacterial growth and both are highly effective for a range of conditions.
So, exactly what is doxycycline mono used for? And how does it vary from doxycycline hyclate?
Well, the key differences between doxycycline monohydrate and doxycycline hyclate is their structure and water solubility. But these differences do not have an effect on how well either works once absorbed in the body.
A 1984 study with 12 volunteers taking the oral forms of both medications found that “there was no difference in absorption and bioavailability between the two preparations.”
Monohydrate and hyclate are simply two different salt forms of doxycycline, with each salt form possessing slightly different absorption properties. Both are sold in tablet and capsule form, but there’s no significant difference in use between doxycycline tablets vs capsules — it all comes down to preference.
Historically, there’s been a significant difference in price between doxycycline monohydrate and doxycycline hyclate, with the monohydrate form of doxycycline more affordable at this time than the hyclate form of this medication.
However, this can vary based on the drug’s manufacturer.
Doxycycline monohydrate and doxycycline hyclate are equally effective in their role as antibiotics. If you’re prescribed doxycycline for a bacterial infection, either type of medication will help to slow down or stop the growth of bacteria and aid in your recovery.
Doxycycline is one of the world’s most common antibiotics, prescribed to treat everything from acne to a range of other bacterial infections. Our guide to doxycycline explains how it works in more detail, as well as its dosages, side effects, interactions and more.