Hi, Welcome to health care magic, As you have mentioned you have pain in your shoulder to back. Here, I would like to know that whether you have any history of diabetes or thyroid illnesses or any injury to that joint. There could be several causes of shoulder pain such as rotator cuff injury or tear or rotator cuff tendinitis (inflammation of its tendons). The initial treatments for all these are, 1. Avoid repetitive overhead activities 2. Do not carry any heavy object or bag on affected shoulder or arm. 3. Apply ice packs for about 15 minutes twice or thrice daily. 4. If you have learned how to do shoulder exercises then continue with that it s could be effective . 5. Apply diclofenac based topical ointment which is more effective than paracetamol based.(available over the counter) 6. Can take oral pain killers if pain is very severe. 7. There is no harm in taking Re-nerve Plus,as it is just a multivitamin supplement which is good for nerves (more useful in diabetic patients). If still pain is persisting then proper examination of shoulder joint is required to find the exact cause and if needed x ray and MRI should be done. You can consult nearby doctor or orthopedician who can write X-ray and MRI of the shoulder after taking complete history and thoroughly clinical examination.