Hello,
What is the cause of his oligospermia? If the cause is known then medical or surgical intervention may be effective. Empirically many medical approaches have been tried for treating this condition like using clomid, tamoxifen, vitamin E, testosterone, vitamin C,antioxidants, etc. A deficiency in zinc, selenium, vitamin B-12, folate and antioxidants has a negative impact on the quality of men’s sperm. L-Carnitine and acetyl-L-Carnitine are believed to increase the motility of sperm, by helping the transformation of fatty acids into energy. Avoid stress, alcohol and smoking. It is best to consult a doctor and get your doubts clarified before taking any medication. Hope it helped.
Take care and regards!