In my experience injectables sometimes work better than other "traditional" forms of medication, and I have two explanations for it:
1) There is a definitive "placebo" or mind effect using injectables, "they are more expensive, so they must work better" (patient's viewpoint)
2) If injected in a neural, acupuncture or trigger point you have the combined effects of the two therapies.

I mostly try to avoid injections, because:
1) They are more expensive than convensional dosage forms,
2) They (most of the time) cannot be administered to the patient by him/herself,
3) In every case of injection given some micro trauma is created. Although this can be used for the patient's advantage (point 2 above), it is often unneccesary and painful
4) The possible positive effects of injectables compared to the reasons 1 - 3 given above does not add up.

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Christiaan van Schalkwyk<br />Registered Homeopath (RSA) (M.Tech.Hom (Natal))