Stronger grades have higher potency.

They are more powerful and anti-bacterial properties are higher.

Any honeys from UMF15 to UMF20 are Antibacterial grade and useful for skin therapy.

UMF20-25 is a Superior Anti-bacterial grade for very bad wounds.

Low grades between UMF5 and UMF10 are table grade Manuka honey, safe for daily ingestion.

Low to mid grades for UMF10- UMF15 are called Therapeutic Grade, good for short term consumption.