Tamoxifen vs Generic Brands

I don't think most chemists (in pharmacies) do know. The active ingredients are the same, they have to be but the fillers and binders may differ and it's not just a simple matter of what's better. One that would be fine for me may be less so for someone who is lactose intolerant if there are any lactose traces. There is also the relatively small problem of what might interact in a different way with other medication. I don't imagine these differences are likely to be dangerous but they might possibly build up, with something you take daily over a long time. Non-specific, lingering, not-quite-rightness!