Hydroxychloroquine is very well tolerated, but may present with rare unwanted side effects. One of the most feared side effects of this medication is irreversible damage to the retina, resulting in permanent vision problems. This risk is exceedingly rare, and occurs at the rate of 2% if used for more than 10 years. Prior to starting the medication, you need to have a thorough eye examination by an eye doctor. Detailed eye examinations should be performed at the beginning and then every year after five years of use. Such eye exam helps identify early signs and prevent long-term damage. Some gastrointestinal side effects you may experience are nausea, vomiting, diarrhea, and abdominal cramps. All of which may be avoided by slowly increasing the dose of the medication. Taking the medication with milk or other food could also reduce such side effects. Some of you may experience rashes, hyperpigmentation, or hair loss, which can be minimized by decreasing sun exposure and applying sunscreen. Despite the many side effects, most patient can tolerate this medication without any major problems.