Abstract: A magnetically controllable, or guided, ferrocarbon particle composition and methods of use and production are disclosed. The composition may optionally carry biologically active substances that have been adsorbed onto the particle. The composition comprises composite, volume-compounded particles of 0.1 to 5.0 &mgr;m in size, and preferably between 0.5 and 5.0 &mgr;m, containing 1.0 to 95.0% by mass of carbon, and preferably from about 20% to about 60%. The particles may be produced by mechanical milling of a mixture of iron and carbon powders. The obtained particles are optionally placed in a solution of a biologically active substance to adsorb the substance onto the particles. The composition is generally administered in suspension.