Now, first of all, are u speaking the "Duration of Effect" or when you feeL Withdrawals and the "Elimination Half-life" since if your talking about duration of effects those all seeem to be about normal for a person without a tolerance to fairly low-tolerance levels.
You might be a fast metabolizer of CYP3A4 (Or more than one of the MANY different CYP Liver Enzymes etc.) you can try using things like Grapefruit juice which is weak to strong depending on how much you drink and more importantly has to be 100% Natural and NOT from Concentrate Brand it requires 2x-3x as much as like Tropicana Juice for same Inhibition.
The strongest and easiest available and practical CYP3A4 inhibitor is the Anti-Biotic Clarithromycin I was prescribed it at 500MG once a day in one dose. It came in 250MG Pills and I read it is strong like 90%+ Inhibition.
I don't advise trying this on long-acting drugs like Methadone because it varies so much in potency due to different rates of metabolism and if you take it daily than bad things could happen. For an acute dose just be very careful I don't think it increases the effects much in potency but I read it does though.
I know for fact it will make for me Oxycodone lasts slightly longer and when I snort without a tolerance a line I only need like instead of roughly 7.5 or at most 10MG for the first line. I only need 5MG for the next line and each one every hour. Problem is the dose half-life will build-up despite the duration of the effect being over.
Now I don't if you tried using CYPY Liver Enzyme Inhibitors and things like Codeine require CYP2D6 to make Morphine and Inducers for CYP2D6. One beer with a small dose and maybe valerian root are one of the very few Inducers I know of. I can definitely say when I used like roughly 1 Beer before my Codeine Dose it felt way more Euphoric presumably due to more Morphine being metabolized. I read most people metabolize roughly 5-10% of Codeine Dose to Morphine and people of African "genetics" are more likely to produce more Morphine. I read some people actually overdose from only 30MG Codeine in very "FAST Metabolizers of CYP2D6 Liver Enzyme" but I DON'T recommend using Alcohol with any Drug but with only a small amount not enough to feel any effects and hopefully only just induce some CYP2D6 Liver Enzymes into making more Morphine from your Codeine Dose would be safe.
That's just to give you an idea of how it works.
