It took us six weeks to really see a significant improvement but things did improve slightly week by week after two weeks.
3 weeks to see a difference
The cold sweats and diarrhoea stopped within 24 hours. We're going into week 2 dairy free (she also has prescription formula when I'm at work) and her nose is no longer congested and mucus nappies have now also stopped. She still doesn't sleep well and does struggle with wind and possibly reflux at night but I'm hoping that'll improve over the next couple weeks. With my older daughter it took around 6 weeks to see a difference but her allergy was severe x
Took me about 6-8 weeks and saw a masssssssive difference!
Literally within 48 hours I had a completely different baby, I was so surprised. I felt so guilty I didn't do it sooner.