Suppose twelve people say they slept better after a residential programme. Their accounts deserve attention. During the visit, though, they may also have changed their hours, stopped commuting and had help with meals. Which change made the difference? The accounts alone cannot separate them.
A comparison group helps researchers ask what would have happened without the treatment. The outcome matters too. Fewer missed workdays and a change in a laboratory marker answer different questions. Look for what was measured, how long people were followed and whether anyone left because of unwanted effects.
Try rewriting a headline as a narrow sentence: this preparation was studied in these people for this length of time, and this is what the researchers measured. If you cannot fill in those spaces, you have found the limits of the report. That is a better reason to read the study than either enthusiasm or suspicion about its origin.
Further reading: Ayurvedic medicine: evidence and safety (NCCIH)