The invention provides methods of inhibiting angiogenesis in an individual by administering a composition (such as protein containing composition) comprising colchicine or thiocolchicine dimer. The composition is in an amount that is effective in inhibiting angiogenesis but is in some embodiments insufficient to induce significant cytotoxicity in the individual. The methods described herein are useful for treating angiogenesis-associated diseases, such as age-related macular degeneration, diabetic retinopathy, rheumatic arthritis, psoriasis, and cancer.