True sunflower seed allergy is rare — it appears mostly in case reports rather than large studies, and occupational sensitisation (from breathing sunflower dust in food processing) is more common than dietary allergy. When allergy does occur, it involves a heat-stable protein, meaning roasting does not help.

The most important practical concern for people on elimination diets is sunflower lecithin, which is increasingly replacing soy lecithin in chocolate, baked goods, and supplements. This creates a relatively new hidden exposure route. Refined sunflower oil typically has very low protein content and is tolerated by most sunflower-allergic people, but cold-pressed and unrefined sunflower oils carry more protein and present higher risk.