Doses below the standard 20 mg were linked to milder side effects, especially before menopause. Mattias Hammarström’s thesis studied Tamoxifen, a medicine that blocks estrogen’s effect on breast tissue. The studies involved healthy women and explored options for breast cancer prevention. They tested lower doses and endoxifen, an active substance the body makes from Tamoxifen. Endoxifen was also studied as a medicine taken directly. The clearest findings were in women who had not reached menopause. Lower doses were linked to less severe side effects. Low endoxifen blood levels were also linked to drops in breast density. Those drops were similar to those seen with the standard 20 mg dose. Breast density describes how much dense tissue appears on a breast X-ray. Side effects also mattered for staying with the medicine. Women whose symptoms, such as hot flashes, worsened early were less likely to keep taking it later. The article did not give exact lower doses or the size of the side-effect changes. Less dense breast tissue does not prove fewer cancers. These studies measured breast density, not whether the lower doses prevented cancer. Larger studies that follow women for longer are still needed. For BioSocial members, this highlights the value of tracking symptoms alongside results. Notes on dose, hot flash frequency, and missed doses could add context to breast density reports. Comparing notes with the community can capture daily experiences that test results alone miss. Those shared patterns cannot establish how well a dose prevents cancer. What patterns have you noticed between your dose, side effects, and ability to keep taking Tamoxifen?