The most common peach juice side effects are the result of a peach allergy. Do not drink peach juice if you are allergic to or sensitive to peaches. Symptoms of a peach allergy vary between people, but can include redness or swelling of the mouth, tongue or lips. Some people may experience throat swelling due to an allergy. A skin rash or redness can also be a sign of an allergy.
Other possible peach juice side effects include vomiting, stomach ache, fainting and lethargy. If you experience any of these side effects, consult a doctor. These side effects are not common, but can happen due to consuming excess vitamins or other nutrients.