You can buy castor oil from various online stores that offer high-quality, organic, and cold-pressed options. Some reliable sources include:

• Oliemeesters, which sells organic and cold-pressed castor oil in bulk

• More Natural, offering 100% organic castor oil specifically for hair treatment, with different sizes and qualities available at discounted prices

• iHerb, which stocks castor oils known for moisturizing and soothing skin

• Skin District, where you can find KITSCH Organic Cold-Pressed Castor Oil

• Laboratorium Discounter, providing extra pure, first-pressing cold-pressed castor oil in environmentally friendly glass bottles with argon filling for freshness

• Holland & Barrett, selling cold-pressed 100% pure organic castor oil suitable for hair and skin health

• Ayumi, offering pure cold-pressed castor oil that stimulates hair growth and nourishes the scalp, vegan and natural

• YouWish, with cold-pressed castor oil used in cosmetics for moisturizing and promoting hair growth

These vendors typically ship online, allowing you to purchase castor oil conveniently. Look for "cold-pressed" and "organic" labels to ensure quality and purity.