Doxycycline is one of the antibiotics that is known to cause skin hypersensitivity to light, which is why you should avoid sun exposure while taking them. Since laser hair reduction and hair reduction using intense pulse light therapy utilize "light" as the mode of therapy, it would be very wise to avoid them or any exposure to high energy light devices. I recommend at least a week off antibiotics before I will entertain such a treatment, and even then, I suggest a test spot to see how the skin will respond over a day or two. You have to be cautious because the light energies delivered necessary to allow for hair reduction, while normally very safe, can cause unintended burns in the areas treated if you are taking certain medications known to cause the skin to be more "sensitive." I typically recommend being off antibiotics (and certain other medications) completely for a minimum of 1 week, preferably longer, and then I still proceed with caution. Find a medical doctor that has had experience with hair reduction devices and let them know the medications you are taking. After a thorough evaluation, they will be able to better guide you in the next steps you should take to achieve the goals you desire. Good luck.