Losing 10 to 20 strands of hair daily is completely normal and actually well below the average natural shedding of 50 to 100 strands a day. You do not need to worry. The active ingredient in the shampoo you mentioned is ketoconazole, an antifungal primarily used for dandruff, scalp flaking, or specific pattern hair loss. Since your shedding is within a healthy range, this medicated shampoo is not the right treatment for you and could cause unnecessary scalp dryness. You likely do not need any hair loss treatment. Simply use a gentle, regular shampoo unless you notice visible thinning or scalp irritation.