I've shared elsewhere here that I actually took Fosamax years ago for a few months and then had right leg pain, as you, hip down to my ankle. I could barely walk. I couldn't think of anything else that it could be so stopped the Fosamax and it abated. I informed my Dr. I would not continue. My bone density stayed pretty much the same (~-2.4 femoral neck/hip and -3.5 spine) for 10 years then in 2023 my spine numbers worsened to -3.8 and I researched what I should take. Friends and family were taking Reclast without issue so I decided to go with that, even knowing it was in the same class of drugs as Fosamax. When my Dr. ordered it, the pharmacy flagged it as contraindicated because my chart showed an allergy/reaction to the Fosamax. We decided to override it and do it anyway. I did all the things, Tylenol, hydration prior and the infusion itself was uneventful but about 10 hours later I woke up feeling I had been hit by a truck-rib, side and back pain, fever, dizziness. Those symptoms slowly went away over the next 24 hours but about 8 weeks later, I began with the right leg musculoskeletal pain again. It continues to flare up 18 months in and lasts for a month or two then stops. Related or not, now I have severe osteoarthritis in that right knee and seeing PT for exercises to strengthen my supporting muscles and hoping to avoid a knee replacement. For that, I did do one steroid injection but you can only do so many and it may worsen the OP. I take Calcium, Vitamin D and have added collagen peptides/fortibone powder to my daily routine as well as tumeric powder in foods and tumeric/ginger tea. I told my Dr. I won't be taking it again. I will have a DEXA next week as it's been 2 years and will see if any changes. It seems you are making good progress with your regimen. My point here is that if you had trouble with Fosamax, you may have trouble with Reclast as they are both bisphosphonates but there's no way to know and no way stop it once you have the infusion. I don't think anyone knows how long it stays in your system. Others here say even if you take something else, gains have to be locked in with Reclast so I am off meds for good I think. I wish you the best making a decision.