The single most common way buyers lose money on a product like this is discovering at day 75 that the refund window closed at day 60 — worth a two-minute fix.
The guarantee window is calculated from your purchase date, not when you open the bottle — a calendar reminder removes any ambiguity about when the clock actually runs out.
Set a reminder for both a fair-judgment check-in around week seven or eight and the hard guarantee deadline at day sixty, so neither date catches you off guard.
60-day money-back guarantee, per the manufacturer.