Some herbs have shown potential in improving bone density / reducing symptoms of osteoporosis. Herbs high in isoflavones such as soy, red clover, and flaxseed show promise, but more human studies are necessary.
Recipes to Help with Osteoporosis
Osteoporosis and Herbs – Research
Isoflavones reduced lumbar spine bone loss in women. From: Atkinson, C., Compston, J. E., Day, N. E., Dowsett, M., & Bingham, S. A. (2004). The effects of phytoestrogen isoflavones on bone density in women: a double-blind, randomized, placebo-controlled trial1-3. The American Journal of clinical nutrition, 79(2), 326-333
Red clover isoflavones were effective in reducing bone loss in rats. From: Occhiuto, F., Pasquale, R. D., Guglielmo, G., Palumbo, D. R., Zangla, G., Samperi, S., … & Circosta, C. (2007). Effects of phytoestrogenic isoflavones from red clover (Trifolium pratense L.) on experimental osteoporosis. Phytotherapy Research, 21(2), 130-134.
Bone density improved after women took extracts of isoflavones from red clover. From: Clifton-Bligh, P. B., Baber, R. J., Fulcher, G. R., Nery, M. L., & Moreton, T. (2001). The effect of isoflavones extracted from red clover (Rimostil) on lipid and bone metabolism. Menopause, 8(4), 259-265.
Essential oils of sage, rosemary, thyme, juniper, pine, turpentine, and eucalyptus and their constituents of thujone, eucalyptol, camphor, borneol, thymol, alpha-pinene, beta-pinene, bornylacetate, and menthol inhibited bone resorption. From: Mühlbauer, R. C., Lozano, A., Palacio, S., Reinli, A., & Felix, R. (2003). Common herbs, essential oils, and monoterpenes potently modulate bone metabolism. Bone, 32(4), 372-380. Link: http://dx.doi.org/10.1016/S8756-3282(03)00027-9
This article discussed existing research on phytoestrogens, in plants (soy and flaxseed) reducing bone loss in women. From: Arjmandi, B. H. (2001). The role of phytoestrogens in the prevention and treatment of osteoporosis in ovarian hormone deficiency. Journal of the American College of Nutrition, 20(sup5), 398S-402S.
Flax and low dose estrogen reduced bone loss in rats without ovaries. From: Sacco, S. M., Jiang, J. M., Reza-López, S., Ma, D. W., Thompson, L. U., & Ward, W. E. (2009). Flaxseed combined with low-dose estrogen therapy preserves bone tissue in ovariectomized rats. Menopause, 16(3), 545-554.