What are the side effects of flaxseed oil?
Dec 10, 2025
Source: Cainiu Health
Dr. Huang Yuhong
Introduction
Side effects of flaxseed oil generally include gastrointestinal discomfort, impaired blood clotting, lipid oxidation, worsening of diarrhea symptoms, and allergic reactions. Flaxseed oil is rich in unsaturated fatty acids; excessive consumption or initial use may cause bloating, nausea, and other discomforts, mostly due to poor gastrointestinal tolerance to the oil or insufficient timely breakdown by digestive enzymes.
Side effects of flaxseed oil generally include gastrointestinal discomfort, impaired blood coagulation, lipid oxidation, worsening diarrhea symptoms, and allergic reactions. Detailed analysis is as follows:
1. Gastrointestinal discomfort: Flaxseed oil is rich in unsaturated fatty acids. Overconsumption or first-time users may experience bloating, nausea, and other discomforts. These reactions are mostly due to gastrointestinal intolerance to fats or insufficient timely breakdown by digestive enzymes.
2. Impaired blood coagulation: Components in flaxseed oil may mildly inhibit the activity of clotting factors. Long-term and excessive consumption could prolong blood clotting time, increasing the risk of bleeding in individuals with bleeding tendencies or those taking anticoagulant medications.
3. Lipid oxidation: Flaxseed oil has poor stability. If improperly stored or heated at high temperatures during cooking, it is prone to oxidative degradation. Consuming oxidized oil may cause dizziness, fatigue, and other discomforts due to irritation from harmful substances, and may also increase metabolic burden on the body.
4. Worsening diarrhea symptoms: Flaxseed oil has a mild laxative effect. In individuals who already have diarrhea or gastrointestinal dysfunction, its consumption may stimulate increased intestinal motility, thereby exacerbating diarrhea and disrupting the body's water and electrolyte balance.
5. Allergic reactions: A small number of people may be allergic to components in flaxseed oil, experiencing symptoms such as skin itching and rashes after consumption. In severe cases, breathing difficulties may occur. These reactions are usually related to individual immune responses.
Flaxseed oil should be consumed in moderation to avoid excessive intake. Use low-temperature methods such as cold dressing when preparing food, and store it sealed and away from light.
