Do mosquito patches really work? Or do I need to supplement with repellant?

Yes. Mosquito repellent patch is effective. It is safe for baby as long as you do not stick it directly on their delicate skin. You can stick it on their shirt, their playpen or stroller. You can use bug repellent for extra protection. I personally use California baby bug repellent on my 6 months old boy. This insect repellent is very effective. Mosquito did not bite on area which I have applied the repellent. You can get the repellent from Watsons!