Hi mama! Usually 3-5 days lang makikita mo na if hiyang or hindi sa LO, look out for digestive changes like constipation, diarrhea, rashes, or kung mas clingy/fussy siya than usual, pero honestly some babies take up to 2 weeks pa bago mag-adjust completely. A few of us moms dito nag-switch ng formula and nakita namin agad ang difference sa poop consistency at skin, pero puwede ring transition period lang yan kaya don't panic agad if slightly off pa for a few days. Best talaga kung i-check mo rin with your baby's doc para sigurado at para makakuha sila ng right guidance based sa specific needs ni LO at sa current formula nyo!