The aim of this study is the effect of Zataria multiflora boiss capsule on postpartum pain. It is a clinical, trial, randomized, and double-blind research will be done on 105 mothers, with normal vaginal deliveries. Inclusion criteria: 18-35 years of age; after at last 2 hours of their childbirth; gestational age is between 37-42 weeks; with no medical conditions; not high-risk pregnancy; no problem at childbirth; having moderate to severe pain. Exclusion criteria: Mother needs surgery and postpartum anesthesia received after the delivery; mother is suffering from serious complications after delivery. Shirazi thyme capsule, ibuprofen, and acetaminophen are uniformly and with codes A and B and C will be put in envelopes by the pharmacist and, then, based on random numbers will be given to individuals. Mothers, from 2 hours to 24 hours after delivery, will be studied in postpartum care unit of Ahvaz Imam Khomeini hospital. Before the intervention, the amount of pain will be measured and recorded with pain ruler and, then, the mothers will be given the first capsule and an hour after intervention, the mother's pain will measured and recorded with pain ruler again. Next capsules will be given to mothers every 6 hours and on their request.