Does an even dimensional anisotropic form represent an even number of square classes?

Question

I'm wondering if an even dimensional anisotropic form $\phi$ over a formally real field $F$ represents an even number of square classes (if it represents a finite number of square classes), that is, elements of $F^*/(F^*)^2$ but I do really know how to tackle this problem.
Another similar question would be if an even dimiensional anisotropic form which is also a torsion element of the Witt ring represents an even number of square classes.
I believe that at least the last statement must be true but I don't know how to solve it.
Any help or hint would be appreciated.
Thanks in advance

Answer 1

No. For example, any anisotropic form over $\mathbb{R}$ represents a unique square class (either $[1]$ or $[-1]$).