As per our natural instincts and human tendency, we tend to concentrate more on what is allowed than what is not allowed. Let's take a peak into what you are not allowed to do if you believe in Hinduism. The most important point- You are prohibited from consuming beef if you are a Hindu as cow is considered as a sacred animal in Hindu religion. Adultery is not at all allowed for female and male. Women are forbidden from entering the temples during the menstruation period. Premarital sex is considered as a sin. Mistreating animals is considered as a sin. Cutting of hair and nails on Saturday is considered inauspicious. Hindus are pure vegetarians as killing of animals in a sin in Hinduism. Person who has consumed non-vegetarian food or alcohol should not enter a temple until and unless, he or she has taken a bath. Wasting food is one of the biggest sins. Feel free to add more information as it would be helpful for the community.