The absorbency "Light" can be used at the end of menstruation or by women and girls with very light menstrual flow who use a specific hormonal IUD or pill. This absorbency provides maximum comfort, as the panty is extremely thin in the crotch (1 mm).
The suction strength "Medium" is ideal for the 2nd or 3rd day of menstruation, a perfect compromise between absorbency and comfort in the crotch.
The absorbency "Super" is ideal for the start of menstruation, for nighttime, or for anyone who has a heavy menstrual flow throughout their entire period. The thickness here is certainly a bit more substantial (but still much thinner than a sanitary pad, as it is less than 3 mm), but the absorbency of the slip is unbeatable.
In a word: To cover all variations of your menstrual flow, it may be sensible to have all absorbency levels.
