Why do I feel nauseous on keto?

This is usually a sign of liver or gallbladder problems. Try to consume purified bile salts and see if that helps.

Also, various kinds of sugar alcohol could cause digestive problems. Try to cut back on them and only use a small amount.

Adjust the vegetables you eat; maybe you need to switch to different ones due to sensitivity. You can consume fermented vegetables in this case as it may help.

Avoid dextrose and maltodextrin.

Sometimes people add too many fats on a ketogenic diet without getting used to the quantity gradually. This can cause nausea as well.