Long-term Eucerin users... Does it continue to work??

I discovered Eucerin (and the dual serum hype) about 8 months ago now. I picked a bottle up on a whim, having already tried sooo many things for my melasma, and noticed a huge difference within just days of using this product. For the first few weeks my melasma faded SO MUCH and I was over the moon, however it kind of seems to have stopped. My melasma hasn't come back and is still faded, but it's like it's stopped fading it (I was hoping it might fade completely away eventually).

So my question is... Has anyone continued to see great results with long-term use? I've been using it for 8 months consistently every single day (morning and evening) accompanied with their anti-pigment SPF and anti-pigment night cream, but my results are still very similar to how they were after one month of use.

Any thoughts or tips about how I could be getting more out of the product?