God, I'm going to set a record for posts suggesting the poster do nothing yet. I think you've also got your neurotransmitters and amino acids confused. The amino acid most responsible for serotonin is tryptophan. The pseudo amino acid most associated with GABA is taurine. Glutamine is most associated with glutamine, which is a very important neurotransmitter for mental health, particularly depression and bipolar. But again, I don't really see you needing that coming off of methadone, which affects all neurotransmitters including dopamine but which again if you up these while your brain is still trying to adapt back to functioning without your drug it can make withdrawal harder.
Just one other specific answer to what you mentioned -- the only one you mentioned I'd think is going to be useful is the fish oil. The others don't seem related to what you're trying to accomplish very much except perhaps tyrosine, but not for energy, for it's effect along with B6 in affecting certain neurotransmitters. But I'd skip it, you're trying to get your body back to working normally, so again, I'm not sure you need to detox at all as much as set out on a new, healthy lifestyle full of good organic healthy food rich in antioxidant-abundant veggies.
I would add, Vitamin C is not very useful to you here. In large quantities it's good for getting drugs out of the system by washing them out to pass urine tests, but C as a water soluble vitamin isn't that effective for the liver. The alpha lipoic acid mentioned above and glutathione are far superior antioxidants for the liver and work specifically there and with fat soluble areas of the body. The safest and best way to get glutathione into the liver since it's not very bioavailable as a supplement is to juice wheat grass. That may in fact be all you need if methadone is the only thing you're recovering from, but again, if you're still using it or just quit, flushing the liver will make withdrawal more difficult.
Before this question can be answered we need to know the following: detox from what, detox what (liver, colon, kidneys?), whether you're still taking what you're planning to detox from or not, whether you take medication or not (milk thistle, for example, and other liver cleanses can take medication out with them before they have a chance to work), and whether you need to detox at all or just start a new life by eating better and living a healthier lifestyle. Opiates aren't really all that liver toxic compared to, say, acetominophen or alcohol and you don't want to speed it out of your system if you're close to having quit because that will make withdrawal even worse. I would say the fish oil can be helpful with easing withdrawal symptoms according to many people. So we need a whole lot more info before you do anything.
Probiotics are important in detoxification, especially for removing dangerous products of estrogen metabolism. If it stays in your system and recirculate, these estrogen toxins can generate a number of cancers in both males and females.
High fiber diets are important because the fiber will absorb a number of toxins, allowing them to be eliminated.
A nutrient that improves gut detox is called N-butyrate, it's a short chain fatty acid. It is a nutrient used by intestinal cells and has specific cancer inhibiting ability for a number of cancers. Sweating is also good for detox. Vitamins, minerals, and flavonoids. Vitamin C (ascorbate), natural
forms of vitamin E, selenium, magnesium, all the B vitamins, the omega-3 oils, GLA (gamma linolenic acid), and a diet of deeply colored vegetables
and some fruits. Some nutrients interfere with certain enzymes grapefruit juice prevents enzymes that turn acetaminophen (Tylenol) into a deadly toxin, protecting against Tylenol’s extreme toxicity to the liver and kidneys.
That being said! grapefruit juice can also prolong the effects of caffeine by preventing the liver from detoxifying it. The following protects against toxicity. Hesperidin (oranges), Naringenin (grapefruit), Resveratrol (grape skins), Quercetin (onions, teas, apples, and most vegetables),
Apigenin (celery, parsley, and ginkgo biloba), Ferulic acid (fruits),
Chlorogenic acid (Mackintosh apples, blueberries, eggplant).
Indole-3-carbinol (broccoli, Brussels sprouts and other cruciferous vegetables), Isothiocyanates and sulforaphane (broccoli and Brussels sprouts), Taurine (an amino acid buy as a supplement),
Glutathione (supplied by N-acetyl L-cysteine, ellagic acid and alpha-lipoic acid all as supplements), Glycine (an amino acid supplement high amounts can cause excitotoxicity), MSM (methylsulfonylmethane a supplement).
Curcumin (from the spice turmeric, buy a supplement),
Astaxanthin and canthaxanthin (from all vegetables and fruits and also as a supplement called mixed carotenoids.
The following is great for the Liver! Lecithin (phosphatidylcholine),
Curcumin protects the liver and improves bile flow,
Alpha-lipoic acid protects the liver from some powerful toxins and from hepatitis C and A damage.
Silymarin (from the milk thistle plant) protects the liver and brain and
stimulates liver regeneration.
Vitamin C (as magnesium ascorbate) protects the liver from free radical damage,
Magnesium protects the liver from free radicals and inflammation and increases glutathione levels