Hi Geralding, how old is your baby? Wouldn't recommend it unless your baby is at least 6 months old. The commercial ones are not as safe as homemade. You can make this yourself pretty easily.
1) Buy organic brown rice and use a food processor to blend it till powder
2) Buy the si sen from Chinese medical hall, wash it, sun dry it then blend till powder
3) Mix the brown rice powder and si sen powder and you are done!
If you can, I would also suggest you add anchovies. Buy those with bones still intact, remove the head and wash it. Pan fry on low heat till its crispy. Put in the food processor to blend till powder.
To cook, just add water in a pan and put a table spoon of the brown rice, si sen powder. When mixture boils, turn off heat and add anchovies powder. Stir and serve.