Intramuscular testosterone injections are much affordable than the expensive testosterone gels or creams. Injections are administered in a small dosage (about 200 - 300 mg) every 2 - 3 weeks. The cost of injectable testosterone is about $80 per dosage.Testosterone gels and creams may cost you about $200 - $500 for a month's supply. Side Effects. Although, testosterone injections are comparatively safer than gels and creams, they still have the potential to induce certain side effects.njections are administered in a small dosage (about 200 - 300 mg) every 2 - 3 weeks. The cost of injectable testosterone is about $80 per dosage.