Oral Micronized Progesterone: Appetite & Cravings Changes Explained

Does oral micronized progesterone change appetite or cravings?

Table 7 of the label comes from a 3-year trial in postmenopausal women: 178 took cyclic Prometrium 200 mg with conjugated estrogens 0.625 mg and 174 took placebo with no hormones. Breast tenderness was 27% vs 6%, abdominal bloating 12% vs 5%, headache 31% vs 27%, dizziness 15% vs 9%, and nausea or vomiting 8% vs 7% [1]. The active arm also took estrogen, so those figures cannot be assigned to progesterone alone [1].

In a smaller trial of estrogen-primed postmenopausal women with secondary amenorrhea (25 on Prometrium 400 mg, 24 on placebo), dizziness was 24% vs 4%, nausea 8% vs 0%, and abdominal bloating 8% vs 8% [1].

The label's adverse-reaction tables do not list appetite or craving changes, and no trial discussed here tests them for micronized progesterone. This is a limit of the evidence, not proof of no effect [1].

What the label says about drowsiness and dizziness

The label directs that the 200 mg endometrial-protection dose be taken as a single daily dose at bedtime, and its patient information says to take it at bedtime because some women become very drowsy or dizzy [2][1]. The label warns that Prometrium may cause transient dizziness and drowsiness and should be used with caution when driving a motor vehicle or operating machinery [1].

Does the evidence say anything about weight?

In the 875-woman PEPI trial, which used conjugated equine estrogen with either medroxyprogesterone or micronized progesterone, women assigned to conjugated estrogens alone reported no increase in perceived weight. Those on the medroxyprogesterone regimens reported less perceived weight gain than placebo (odds ratios 0.61 to 0.69). That finding concerns medroxyprogesterone, not micronized progesterone. Only progestin-containing regimens were significantly associated with more breast discomfort (odds ratios 1.92 to 2.27). Anxiety, cognitive and affective symptoms did not differ by treatment assignment [3].