A fatty acid concentrate capable of increasing the activity of male hormones (testosteron, androstandiol or androstendion) is prepared by the steps comprising treating body liquids, animal organs, fatty oils and other lipoid-containing materials to extract a fatty acid fraction therefrom, partitioning the fatty acid fraction between mixtures of solvents which form two phases in order to separate the fatty acids from impurities such as hormones, fats, salts, sterols, separating the solid fatty acids by treatment with heavy metal salts treating the remaining fatty acid fraction in solution with bromine, removing the precipitate formed and debrominating the non-precipitated substances to obtain the desired agent. The starting materials may be subjected to acid or alkaline hydrolysis and the hydrolysate, acidified if required, extracted with a solvent such as benzene or ether. In the case of certain materials rich in sterols and phosphatides, e.g. testicles and suprarenals, the hydrolysis may be dispensed with and the material purified by freezing out with acetone, the cold acetone-soluble part being subjected to the solvent distribution process and the insoluble part first hydrolyzed. The distribution treatment is effected by the successive use of solvents consisting of aqueous alcohol and petroleum ether, aqueous alkaline alcohol and benzene, and aqueous pyridine and benzene, the substance containing the active material being present in the petroleum ether, the benzene, and the pyridine layers respectively. In an example, the pyridine layer as above obtained is acidified and shaken with benzene, the residue of the benzene solution dissolved in alcohol and treated with lead acetate and filtered. The filtrate is acidified with nitric acid extracted with ether. The fatty acids obtained from the ether solution esterified, dissolved in petroleum ether and brominated. A precipitate is formed which is removed, the solution evaporated and the residue debrominated in methyl alcohol, saponified, acidified and shaken with benzene. The dry residue from the benzene is dissolved in oil and injected with testosterone. Materials specified as suitable sources are testicles, fatty oils, urine, blood, liver, wheat germs, egg lecithine, yeast. The Specification as open to inspection under Sect. 91 includes a number of examples describing the preparation of hormone activators from various sources of the above-named classes by methods suitable for the separation of fatty acids, these methods including in some instances partition of the fatty acid fraction between non-miscible solvents as above mentioned. This subject-matter does not appear in the Specification as accepted.ALSO:A fatty acid concentrate capable of increasing the activity of male hormones (testosteron, androstandiol or androstendion) is prepared by the steps comprising treating body liquids, animal organs, fatty oils and other lipoid-containing materials to extract a fatty acid fraction therefrom, partitioning the fatty acid fraction between mixtures of solvents which form two phases in order to separate the fatty acids from impurities such as hormones, fats, salts, sterols, separating the solid fatty acids by treatment with heavy metal salts, treating the remaining fatty acid fraction in solution with bromine, removing the precipitate formed and debrominating the non-precipitated substances to obtain the desired agent. The starting materials may be subjected to acid or alkaline hydrolysis and the hydrolysate, acidified if required, extracted with a solvent such as benzene or ether. In the case of certain materials rich in sterols and phosphatides, e.g. testicles and suprarenals, the hydrolysis may be dispensed with and the material purified by freezing out with acetone, the cold acetone-soluble part being subjected to the solvent distribution process and the insoluble part first hydrolyzed. The distribution treatment is effected by the successive use of solvents consisting of aqueous alcohol and petroleum ether, aqueous alkaline alcohol and benzene, and aqueous pyridine and benzene, the substance containing the active material being present in the petroleum ether, the benzene, and the pyridine layers respectively. In an example, the pyridine layer as above obtained is acidified and shaken with benzene, the residue of the benzene solution dissolved in alcohol and treated with lead acetate and filtered. The filtrate is acidified with nitric acid and extracted with ether. The fatty acids obtained from the ether solution esterified, dissolved in petroleum ether and brominated. A precipitate is formed which is removed, the solution evaporated and the residue debrominated in methyl alcohol, saponified, acidified and shaken with benzene. The dry residue from the benzene is dissolved in oil and injected with testosterone. Materials specified as suitable sources are testicles, fatty oils, urine, blood, liver, wheat germs, egg lecithine, yeast. The Specification as open to inspection under Sect. 91 includes a number of examples describing the preparation of hormone activators from various sources of the above-named classes by methods suitable for the separation of fatty acids, these methods including in some instances partition of the fatty acid fraction between non-miscible solvents as above mentioned. This subject-matter does not appear in the Specification as accepted.