Generally, no, although we suggest that you consult with your physician before taking our fish oils if you have a known medical condition or are taking medications (including blood thinners). If you experience repeated burping or a bad taste, your supplement may be rancid (oxidized), or your body may not be manufacturing enough lipase, the digestive enzyme our bodies make to digest fats and oils. If you haven’t ingested fish oils for a long time, it might take a week or so for your body to adjust and make more of this enzyme to digest fats and oils. Taking fish oil with food, especially fat, can also be helpful for digestion.