Subgroup analysesSubgroup analyses by dose of BHT suggested that higher doses of BHT may be associated with more effectiveness but also higher risk of adverse effects .
There was low to moderate quality evidence that BHT in various forms and doses is more effective than placebo for treating moderate to severe menopausal hot flushes .
There was some evidence to suggest that higher doses of BHT are associated with greater effectiveness but also with higher risk of adverse effects .
No data are yet available about the safety of BHT with regard to long-term outcomes such as heart attack , stroke and breast cancer .
BACKGROUND Various hormone therapies ( HT ) are available to treat  menopausal vasomotor symptoms .
Bioidentical hormones are chemically identical to those produced by the human body , and several types are well-tested and available on prescription .
Many women have opted for bioidentical hormone therapy ( BHT ) on the assumption that it is safer than other forms of HT .
We evaluated the evidence .
OBJECTIVES To determine the effectiveness and safety of bioidentical hormones compared to placebo or non-bioidentical hormones for the relief of vasomotor symptoms .
Lowest Effective Transdermal 17β-Estradiol Dose for Relief of Hot Flushes in Postmenopausal Women: A Randomized Controlled Trial
OBJECTIVE : To investigate the efficacy of micro-dose transdermal estrogen in relieving  menopausal vasomotor symptoms . METHODS : A r and omized , double-blind , placebo-controlled , multi-center trial . Healthy postmenopausal women with at least seven moderate or severe hot flushes per day for at least 1 week , or at least 50 per week , applied transdermal patches with a nominal delivery of 0.023 mg/d 17β-estradiol and 0.0075 mg/d levonorgestrel ( low-dose E2/levonorgestrel ; n=145 ) , 0.014 mg/d E2 ( micro-dose ; n=147 ) , or placebo ( n=133 ) for 12 weeks . The co primary efficacy variables were the mean changes from baseline in frequency and severity of moderate and severe hot flushes at the week 4 and 12 endpoints . RESULTS : At the week 12 endpoint , mean weekly frequencies of moderate and severe hot flushes were significantly reduced compared with placebo with low-dose E2/levonorgestrel ( −51.80 ; P<.001 ) and micro-dose E2 ( −38.46 ; P<.001 ) . Severity scores were also significantly reduced with both treatments compared with placebo . At week 12 endpoint , 41.3 % of women receiving micro-dose E2 were treatment responders ( 75 % or more reduction from baseline in hot flush frequency ; P=.003 compared with 24.2 % placebo ) . In this group , the mean reduction in moderate and severe hot flushes from baseline was approximately 50 % after 2 , 70 % after 4 , 90 % after 8 , and 95 % after 12 weeks . There were no differences between active treatments and placebo regarding adverse events . CONCLUSION : Micro-dose E2 ( 0.014 mg/d ) was clinical ly and statistically significantly more effective than placebo in reducing the number of moderate and severe hot flushes , with a 41 % responder rate , supporting the concept of the lowest effective dose . CLINICAL TRIAL REGISTRATION : Clinical Trials.gov , www . clinical trials.gov , NCT00206622 LEVEL OF EVIDENCE :
Subgroup analysesSubgroup analyses by dose of BHT suggested that higher doses of BHT may be associated with more effectiveness but also higher risk of adverse effects .
There was low to moderate quality evidence that BHT in various forms and doses is more effective than placebo for treating moderate to severe menopausal hot flushes .
There was some evidence to suggest that higher doses of BHT are associated with greater effectiveness but also with higher risk of adverse effects .
No data are yet available about the safety of BHT with regard to long-term outcomes such as heart attack , stroke and breast cancer .
BACKGROUND Various hormone therapies ( HT ) are available to treat  menopausal vasomotor symptoms .
Bioidentical hormones are chemically identical to those produced by the human body , and several types are well-tested and available on prescription .
Many women have opted for bioidentical hormone therapy ( BHT ) on the assumption that it is safer than other forms of HT .
We evaluated the evidence .
OBJECTIVES To determine the effectiveness and safety of bioidentical hormones compared to placebo or non-bioidentical hormones for the relief of vasomotor symptoms .