Final answer:
Complementary and alternative therapies often face challenges such as a lack of evidence-based guidelines and minimal research. However, strong support by allopathic medical providers is not one of these drawbacks; it's been growing, as evidenced by the AMA's support for incorporating alternative medicine in education.
Step-by-step explanation:
The drawbacks of complementary and alternative therapies would include a lack of evidence-based guidelines, minimal supportive research studies, and lack of a long tradition of therapies taught in health care education, but not strong support by allopathic medical providers. In fact, organizations like the American Medical Association (AMA) have resolved to support the incorporation of complementary and alternative medicine in medical education, indicating a growing acceptance among conventional healthcare providers.