At what maximum rate after chemo do you lose your hair?

After 3-4 weeks: Not all chemo drugs cause hair loss. Some will cause partial, others can cause complete hair loss. It is not seen for the first 3-4 weeks. So the first chemo cycle comes free. Then you start thinning your hair with each cycle of chemotherapy and may be bald in 2-3 months. Some patients prefer to trim their hair, so it is easier to manage when they fall all over your dress and bedding.