Ok, I wanted to make sure I got in my 2 cents, as I feel I have some completely different news, very important, to give you. As follows:
1. Methadone is dispensed in 5, 10 and 40 mg pills in the U.S. You don't have 50 mg methadones. PLEASE always check your pill with a pill identifier (drugs.com, or similar) before EVER taking a pill you have bought, regardless of your trust in the person that gave it to you. It's too easy to, plain and simple.
2. Methadone is very unlike other opiates. If you have never taken it DO NOT TAKE MORE THAN 10 MGS, DO NOT. Even if you have a tolerance to other opiates (e.g. hydrocodone, oxycodone, propoxyphene, codeine, morphine) if you have never taken dolophine/methadone, there seems to be little correlation between your first use of it and your tolerance to other opiates. The drug heavily depresses respiration and you need to be very careful. Even taking 10 mgs and taking a booster dose of say 2.5 could put you over the top, and its half life is very long. Literally, you could feel great on 10 mgs your first-tenth time, take an extra 2.5 and be seeing triple. It's just weird like that, can't explain it. After say 20 or 30 doses, your body seems to adjust and 10 mg may never do it again for you, regardless of a break.
3. Methadone is very much anxiolytic (a drug that decreases anxiety, stress, tension), maybe even considerately more-so than benzodiazepines, depending on your reactions to each. However, unline benzo's, you shouldn't feel the need to keep taking more. Follow this instinct and chill with the amount you have in you: it lasts a long time.
4. Do not inject solutions of methadone (often givin in methadone clinics as kool-aid flavored solution) or tablets, as they are made specificly, or largely, specificly for addicts and people who inject. Do not put your beautiful life in risk like this. There is an injectable form, and it is supposed to "hit" you, but do not even consider unless it's injectable form.
5. METHADONE TAKES 1-2 HOURS TO START WORKING. DO NOT TAKE MORE THINKING THAT YOU ARE NOT EXPERIENCING THE EFFECTS OF A DOSE, AS THE DOSE IS NOT YET IN YOUR BLOODSTREAM. This is extremely important.
6. As the literature I have read indicates (take it for what it is, give or take, it depends on the individual of course) methadone does not completely fill your opiate receptors until you reach 40-80 milligrams. Once you reach this much, only suboxone/buprenorphine is strong enough to replace the methadone molecule from the receptor. Taking more or a different opiate is quite likely pointless.
If there are other questions, please feel free to contact me.
BE SAFE.
peace