Several misconceptions surround juice cleanses. If they are not done the right way, the outcome can be disastrous. But if they are executed properly, they can make a world of difference for your body.

Many people think doing a juice cleanse is the quickest and easiest way to lose weight and get healthy, but it’s not that simple. Juice cleanses take discipline and commitment. Depending on the state of your health, it may take longer than a few days or a week to really clean out your system. And it may take a few days of sickness before you start to feel good. Headaches, throwing up and diarrhea are normal. It’s a sign your body is ridding itself of built-up toxins.

Keep in mind that going on a juice cleanse is a drastic change to your body’s nutrient intake and digestive system. It will tamper with your metabolism and even slow it down. When doing a juice cleanse, it’s incredibly important to gradually ease back into eating solid foods.

A good model to follow is to do a cleanse in three stages. If you were doing a three-week cleanse, for the first week, drink only cold-pressed juice. For the second week, ease back into solid foods by adding in raw vegetables. And for the last week, add in lightly steamed veggies, fruits and nuts. Most importantly, when finished with your cleanse eat as clean as possible. Jumping back into old habits too fast will wreak havoc on your system and can lead to sickness and weight gain.

When doing a cleanse, consume highly alkaline foods and drink a large amount of water. Juices should be made from mostly green vegetables including kale, spinach, cucumber and celery. Warm water with lemon is good to drink in the morning to begin flushing out your system. You can also drink herbal tea. Fruits should not be included in the cleanse. The high sugar content will counteract the cleansing properties of the alkaline vegetables. The only fruits that are encouraged during a cleanse are lemon, lime and avocado.

Cleanses are difficult but doable and rewarding if done correctly. The key is to stay focused, committed and to resist the urge to cheat. If a juice cleanse is done properly, it can literally scrub your insides clean from years of damage.