How do experts compare oxycodone vs morphine strength?
Oxycodone is generally considered stronger than morphine when comparing doses by opioid “potency” conversion. A commonly used equivalence is that 10 mg of oxycodone is roughly equal to 15 mg of oral morphine (an oxycodone-to-morphine ratio of about 1:1.5) [1].
That means oxycodone is about 1.5 times as potent as morphine by mouth in typical opioid conversion tables.
What does “1.5 times stronger” look like in practical dose conversions?
Using the common equivalence (10 mg oxycodone ≈ 15 mg oral morphine) [1], the comparative strength works out like this:
- 5 mg oxycodone ≈ 7.5 mg oral morphine
- 10 mg oxycodone ≈ 15 mg oral morphine
- 20 mg oxycodone ≈ 30 mg oral morphine
Does the route of administration change the comparison?
Yes. Potency comparisons depend on whether the drugs are taken orally, given by injection, or delivered via other formulations, because absorption and bioavailability differ. The “10 mg oxycodone ≈ 15 mg oral morphine” figure specifically refers to oral dosing equivalence in standard conversion guidance [1].
If you are comparing an oxycodone formulation to an injected (parenteral) morphine dose, the conversion would be different.
Why can the “stronger” number still be uncertain for individual patients?
Even with conversion ratios, individual response varies based on factors like opioid tolerance, age, liver function, and prior opioid exposure. For that reason, clinicians typically use conversion tables as starting points and then adjust based on pain relief and side effects.
Sources:
[1] https://www.drugs.com/dosage/morphine.html