I have a puppy that is 1 month, we want to buy him a flea collar and shampoo but in the warning it said not be used on puppies under 12 weeks.

What do I use for my puppy to get rid of the fleas?:(

Try a flea comb to remove them. One month is far too young for any flea products. When he is of age, he will need flea treatment and/or preventitive.

Somebody told me that shaving cream kills fleas. I wouldn't think it would harm an animal if men can use it on their face but I can't say that for sure so I wouldn't take the chance on a puppy. I do know however that fleas do drown so giving the puppy a regular bath in Aveeno baby wash & shampoo will rid some of the fleas and help with the itching.
From The doctors book of home remedies for dogs and cats "mix a little garlic and brewer's yeast into your pet's breakfast" may help too.
Is your puppy a house dog or out door pet?

Talk to your vet. I have zero confidence in The doctors book of home remedies for dogs and cats Likely it if full of untested quack remedies. I have heard of giving dogs garlic to prevent fleas, but know on not one shred of evidence it is effective, or safe.

I looked at the dog shampoos at the pet store the other day. One of them said safe for puppies. You can count on such products having been tested and proven safe. Better than any OTC products, are products from the vet.

The flea comb maybe a safer way to remove existing fleas than any bath.

How is it that you have a month old puppy with fleas? At a month old, puppies should still be with their mother and litter. I don't want to beat you up for making the best of somebody else's irresponsibility.

Did the mom stop nursing the pup? With a pup that young , they still need a bottle, and really the only suggestion I have is , a cup of lemon dish soap, a flea comb, and drop the fleas you get into the bubbles, they will die but you will have to do this many times a day. A puppy that little can not handle the toxins in flea shampoo. Good luck .

I'm just now back to being a puppy mommy too!