Normally 50 to 100 hair fall happens everyday. But if its more than that we call it as telogen effluvium. The reasons could be past 6 months if you have suffereddrom major illness like dengue, tyhoid, etc, major surgeries, stress, hormonal imbalance,  nutritional deficiencies like iron deficiency or vit b 12 deficiency etc. So check the Hb, thyroid. In females we have to rule out PCOS, so get ultrasound done. Peptide serums available,oral biotin supplements help in hair loss. Myth about hair loss is shampooing doesn't cause hair fall or hair growth or greying of hair. It just cleans your scalp.