Detoxing comes in many forms so depending the detox can depend on how often you should do it. You can perform a detox in a form of merely removing things from the diet. Or cut out all foods and fas, or do it with a few things included in the diet. We have GAPS/ Gut Restore which is similar to an elimination diet, starting with basics and doing it for a time and slowly adding things back in. Some detox by taking things to force the organs to flush, and some will just eliminate specific substances or foods.
How do I know if I need a cleanse? When you are low on energy and feeling like you are dragging from the time you wake up till the time you go to bed. When your body is aching and inflamed or having digestive issues. These are all good signs you could use a detox of some kind. Because of how well you feel after doing one some people get addicted to that feeling and want to keep doing it. Yet after so long of reducing or limiting foods or forcing a cleanse we become weak, this is cause now we are lacking nor have not maintained enough food or we are flushing and need to rebuild. Just a note that a continued fast for too long, or not eating foods to support rebuilding, and forcing a detox can begin to wear on the body and create a major breakdown. This isn't the point of a cleanse/detox.
Depending on how toxic you are and the state of your body can dictate how often. I do not recommend forcing a flush often and if you have organs that are weak or breaking down you should do a detox to clear and feed at the same time. These people would be those who have autoimmune issues and would do better to do an elimination type of detox or Gut Restoring protocol. Those with severe diseases would want to work closely with someone to manage a cleanse to make sure they are getting support and not worsening the body.
We often need to detox even when we are "healthy" due to toxins in our environment. These toxins are in our cleaning supplies, in our water, and in our air and we have to take daily efforts to reduce them. So it is great to now and again help the body to flush toxins.
Depending on the type of detox/cleanse will depend on the amount and how often you should do it. Detoxing from simulants or things that push us to certain physical or mental states is often good to do a break quarterly. Pushing cleanses with herbs or supplements can be pretty forceful, I would say done at max 2 times a year. Again, not recommended if you have organs breaking down several (autoimmune or severe disease). Fasting done for a 24-hour period can be done weekly or monthly, but I don't recommend doing more than 24 hours. You want to pick the detox and fasting that works for your goals and rebuild your body.
Detoxing is supportive for organs, balancing blood sugar, lowering toxicity, resetting the body overall, and resetting response to stimulants, there can be many reasons to do a detox. I would say Gut restore/ GAPS and Elimination diets are good ways of lowering toxicity and resetting the body. I will actually say that this is the best way to nutritionally support the body and detox. I have an entire series on my FB page about how to do this detox. Here is the link for that series. https://business.facebook.com/UtahFoundationalNutrition/videos/584469736598096/
Needing support to know which cleanse to do and how often feel free to do a survey or set up an appoinement.