Buckthorn and flaxseed are both plant sources of omega-3 fatty acids, which are beneficial for your heart health, skin health, and immune system. However, they have different types and amounts of omega-3s, as well as other nutrients and compounds.

Buckthorn, also known as sea buckthorn, is a berry that grows in cold and dry regions of Asia and Europe. It has a high content of vitamin C, vitamin E, carotenoids, and phytosterols, which are antioxidants that protect your cells from damage and inflammation1. Buckthorn oil can be extracted from the seeds or the pulp of the berries, and each has a different composition of fatty acids. The seed oil contains mostly linoleic acid (LA) and alpha-linolenic acid (ALA), which are both essential omega-6 and omega-3 fatty acids, respectively. The pulp oil contains mostly palmitoleic acid (PA) and oleic acid (OA), which are both monounsaturated omega-7 and omega-9 fatty acids, respectively2. These fatty acids have anti-inflammatory, anti-microbial, and wound-healing properties2.

Flaxseed, also known as linseed, is a seed that grows in temperate regions of the world. It has a high content of lignans, which are phytoestrogens that may have beneficial effects on hormone-related diseases, such as breast cancer and prostate cancer3. Flaxseed oil is extracted from the seeds and contains mostly ALA, which is the same essential omega-3 fatty acid found in buckthorn seed oil. However, flaxseed oil has a higher percentage of ALA than buckthorn seed oil, making it a more concentrated source of omega-3s3. ALA can be converted by your body into eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), which are the omega-3 fatty acids found in fish oil and have more potent health benefits3. However, this conversion is inefficient and depends on many factors, such as your age, gender, diet, and genetics3.

Therefore, buckthorn and flaxseed are not exactly comparable, as they have different types and amounts of omega-3s, as well as other nutrients and compounds. Both can be beneficial for your health, but in different ways.
Buckthorn may be better for your skin health, immune system, and inflammation, while flaxseed may be better for your hormone-related diseases, cholesterol levels, and blood pressure132. However, more research is needed to confirm the effects and optimal doses of these plant sources of omega-3s.