Is it legal to bring any Canadian Tylenol into the US?

Yes, it is generally legal to bring Canadian Tylenol into the U.S. for personal use, as long as it is for a reasonable quantity and not for resale. However, it is advisable to keep the product in its original packaging and to carry a copy of the prescription if it is prescription-strength. Always check the latest regulations from the U.S. Customs and Border Protection or the FDA before traveling.