Your wrong, again.
Tamoxifen has been used successfully to reduce gyno since the 80s:
[Influence of size and duration of gynecomastia on its response to treatment with tamoxifen]. - PubMed - NCBI
- 6 months of Tamoxifen at 20mg per day eliminated gyno in 62% of the group (26/43).
[Testosterone and estradiol levels in male gynecomastia. Clinical and endocrine findings during treatment with tamoxifen]. - PubMed - NCBI
- 20mg/day for 2-4 months = "Gynaecomastia regressed partially or completely in 14 patients, in only 2 was it unchanged. There was no recurrence of gynaecomastia after discontinuing tamoxifen. Side-effects did not occur. It is concluded that tamoxifen is a promising alternative to the surgical treatment of gynaecomastia."
Idiopathic gynecomastia treated with tamoxifen: a preliminary report. - PubMed - NCBI
- 40 mg/day of tamoxifen for 1-4 months results in 80% complete regression of gyno with no long-term side effects observed over a follow-up period of 36 months.
There are a lot more studies showing the successful reduction of gyno through tamoxifen treatment if you wish for me to continue
It's also commonly prescribed in the UK by the NHS for gyno treatment and there is plenty of anecdotal evidence across the forums showing its success.