Whether your herbal supplement is safe or not depends on a few factors. You can’t come to a conclusion that they are completely safe or they are not safe. Here are some of the points that must be taken into consideration:

First and foremost thing that you must find out is that why are you using this supplement. Is it for supplementing the medicine you are taking or curing any particular disorder?

Herbal supplements must be taken as per the recommended dosage.

If you are relying merely on herbal supplements as the cure of any chronic disease, then this would not be a prudent decision. You must follow prescription medicinal course to cure the chronic heath ailment. Herbal supplements are effective. But it takes time. Is that delaying a safe decision?

Some people have allergies to certain substances. It is necessary to read details of all the ingredients present in the supplement. If you are aware of any ingredient you are allergic to, drop the idea of using that supplement. Reading the expiration date is also important while using any supplement.
Herbal supplements are safe if used properly and bought from a reputable manufacturer. But it may cause problems if it interferes with the medications that you are already taking. Patients who take anti-clotting medications such as aspirin, warfarin and clopidogrel must not take ginger and ginseng supplements.
How safe are herbal supplements? The answer to this question differs and depends on situations.