We had a bearded dragon (who passed away from old age, bless her little soul) before we adopted our parrot. She needed a specialty full spectrum bulb all the time, and those cost $80 (we needed to replace it about once a year, since she needed it on all day, every day). When we adopted our BFA, I put the bulb in the living room light fixture. Since we no longer leave it on 12 hours a day, it's lasted over 5 years. Don't really know if it does anything for him, but boy is it bright for us! Im actually considering buying a second one (cost puts me off a bit) for our bedroom because its like a cave in there with standard bulbs lol. But with our guy, his cage is positioned about 6' from a HUGE window, and during the warm months (about 8 months a year here in AZ) he gets to come outside 2-3 hours a day in the natural sunshine, so he really isn't in need of supplemental light. Anyways, I would say if you get the high quality bulbs, they do produce the kind of lighting they promise. Our beardie lived to the ripe old age of 16, and her species MUST have sunlight or they will die, so obviously the bulbs did their job well.