The safety of the product is the same, obviously, no matter where one goes. The toxicity (if any) is the same.
However, there may be customs regulations. If in a pill form, you can bring it (unless it is a drug that is illegal where you are visiting, such as some kind of opioid). If it is some sort of dried fruit or meat, they probably won't let you take it into the country if they find it, due to concerns about bringing exotic pests into the country being visited.
Sale of a natural product is something different, regulated by laws in different countries.
I think Jack has probably interpreted your question appropriately. You would have to declare the goods you are bringing in to the country you intend to visit to the local customs and border protection staff...they will discuss with you what you have and if it is a risk item you would have to surrender it. Don't try to avoid declaring any goods as you risk a monetary fine or being denied entry to the country. You may be able to contact the authorities in your destination country before flying there if you can find them on the internet to discuss the status of your product.
It depends on the county you go to for example the next country to you (Thailand) is hard to bring foods to Thailand usually taken, in Germany they took an empty bottle of water brought from Egypt. Probably in some African countries the restriction of customs is less than Thailand and USA. However, Natural products have certain regulations and also depends on which country you go to take; African or a western country. So you need check that before travelling.
You may need declaration document from FDA in your product and purposes for handling through the countries. Please carry the paper to certify your research purposes. I think should not have any problems. Some countries are very restricted for bringing food or farming products. Like Hawaii, New Zealand, Canada.