Like all of the supplement industry, it will depend on a couple things. One, what are the regulations in your country? How well are they enforced?

In the US, there is next to no regulation or enforcement, so often these things don't contain what they claim to, or not the amount claimed. So you're looking at third party testing groups or just trusting the manufacturer. Mostly the adulteration isn't harmful, but generally inert. So if there's very little or nothing there, it's most likely placebo.

Next - even if you do get the dose of what it claims - I think it's still very likely placebo, extremely weak or extremely variable effect. "alternative medicine" that has consistent effects on most people every time even when they don't know what they're taking isn't usually alternative anymore - we just call it medicine.

All that said - I personally don't see any issue with using a placebo for psychological issues - "it's all in my head" so applying a "just in my head" fix seems reasonable as long as it's working for me.