I wouldn't use a head collar on a puppy, but then again, I would be very reluctant to use one on an adult dog. That's just my opinion - the risk of neck injury is quite high, and they are extremely aversive for the dog, because of the pressure points and nerves located in the dog's face. You also see a lot of people use them and then take them off and the dog still pulls.

What sort of training have you done with him? At 16 weeks he just needs to be taught to walk on a loose leash, the habits you develop now will be habits he has for life. It is best to train him to walk politely now, rather than put a bandaid over it by using a tool like a head collar and have an adult dog who still has the same problem. The half check collars or martingales are helpful, but they won't stop pulling all together, but they would be more suitable for a puppy than a head collar.

Are there any training schools in your area that you could go to? Or get a trainer to do some one on one lessons with you... it is a worthwhile investment