A little over a month ago I conducted a personal experiment where I took 25mg/day doxycycline hyclate in an effort to improve the quality of my skin by reducing collagen breakdown via the inhibition of Matrix-Metalloproteinases (MMPs).

For the duration of the experiment, I consumed approximately 25mg doxycycline in the morning on top of my usual stack of supplements. Unfortunately, due to laziness and lack of time, I don’t have any objective observational data of the effects (i.e., comparative photos taken under identical conditions), so I’ll instead talk about how things appeared. I wouldn’t normally be satisfied with such subjective measurement, but the outcome was so resoundingly bad that I don’t think it matters! :/

Initially, I was perplexed that an ulcer I developed in my mouth was seeming to take far longer than normal to heal; however, this may have something to do with my expectation that healing, especially of oral wounds, would be accelerated.

The one important factor that I intended to measure was if doxycycline supplementation would do anything to increase the production of collagen in the skin. As someone who has experienced the obvious and profound (and positive) effect of oral retinoids on skin texture and quality, I was somewhat disappointed in doxycycline’s effect. Not only was there no (subjective) reduction in the number, severity, or depth of the photo-aging induced wrinkles on my face, but the doxycycline appeared to be making the condition worse!

About two weeks into the experimental period, I was continually dismayed every time I looked into the mirror at what appeared to be a ‘thinning’ of the skin on my face, particularly noticeable on my forehead, as well as more noticeable wrinkles and an overall reduction in any remnants of the youthful glow that Father Time has yet to wrestle from me. Even within the short duration of the experiment, the skin on my face started to take on that ‘papery’ stiffness one associates with the skin of the elderly.

It really was difficult to persist with the regimen in the face of what I felt to be outright failure of my idea, but I did anyway.

About ten days after ceasing the medication, I already feel my skin has mostly regained its normal texture, but I can’t be sure because I didn’t carry out any real quantitative analysis. It has definitely reverted to its normal elasticity.

All in all, I recommend not employing doxycycline to improve the quality of one’s skin. As for why this happened, I can only speculate. If we assume that doxycycline does in fact inhibit the breakdown of collagen, I suppose it could have caused a ’stiffening’ of the skin, which then caused it to appear more wrinkly and deeply lined. The perceived reduction in facial subcutaneous fat my have just been my interpretation of the changed texture. Perhaps it skews the ratio of collagen to elastin, again resulting in a reduced elasticity of the skin.

Regardless, I seem to have discovered for myself why there is apparently no research taking place regarding doxycycline as a potential ‘cosmaceutical’!