Because early reports from the 1980's mentioned that LDN should be taken before bedtime, some people have taken this to mean that peak levels of naltrexone only occur if this drug is taken at night. Since these early reports, researchers have realized that endorphins, unlike hormones, aren't affected by circadian rhythm.

As with any drug, the effective chemical is absorbed and metabolized by the body at a rate that's affected by cytochrome p450 enzymes (genetic influences), other drugs, diet, body weight, general health, dose of the drug, its matrix and fillers, and other factors. Several hours after the drug is metabolized, endorphin levels rise. This varies in individuals and it varies from day to day. Unlike therapeutic levels of naltrexone, the subsidiary effects (rise in endorphins) varies. However, the effect can persist for 48-72 hours and probably longer.

In Dr. Maira Gironi's studies of LDN in MS, which involved daytime dosing, endorphin levels remained significantly elevated 3 months after LDN was discontinued. Obviously, there's more to the the effects of naltrexone than peak endorphin levels 4-6 hours post dose. Just as endorphin levels stay appreciably elevated in a loving relationship, endorphin levels stay appreciably elevated after continued use.

Bottom line, if you're taking a drug intended to induce sleep you take it at night. If you take a painkiller, you take it when you have pain. If you take low dose naltrexone, you take it once daily at about the same time each day, a time that is convenient for you and doesn't cause side effects.

Valerie wrote a great article on LDN dosing [soon to be posted in Val's Thyroid Corner] that describes the controversy and explains why Sammy Jo and I brought the subject up in articles an in our book.  To your good health, Elaine