Swanson Premium Swanson Psyllium Husk 12 oz (340 g) Pwdr Per GMP guidelines set forth by the FDA, most products are formulated for 24 months from the date of manufacture. Liquids and probiotics are formulated for 12 months. Vegetarian Per GMP guidelines set forth by the FDA, most products are formulated for 24 months from the date of manufacture. Liquids and probiotics are formulated for 12 months.