Safe. According to Query 39. com, hops, tocopherols, spirulina and glycerin are safe for breast enhancement. Hop is a kind of plant, and its extract can promote the growth and development of breast tissue. Tocopherol is a vitamin, which can promote the healthy development of breast tissue. Spirulina is a kind of plant, and its extract can enhance the elasticity and toughness of breast tissue. Glycerol is a moisturizing ingredient, which can keep the breast tissue moist and elastic.