Always consult with your child's qualified healthcare provider before introducing any solid foods. If there is a history of food sensitivity or allergic reactions in a family member (mom dad and/or sibling) such as true food allergy, eczema, or asthma, your healthcare provider may recommend that certain foods be introduced slower. There was a study that found when infants were exposed to peanuts between five to nine months they were less likely to have anaphylaxis to them by age five. If your healthcare provider supports the introduction of peanuts at this age, it is always best to use natural organic peanut butter and not hydrogenated, high sugar forms.
See this post about identifying signs of allergies and how to introduce foods you are concerned about.