Is rhodiola safe during pregnancy?

What does the evidence say about rhodiola during pregnancy?

1. NCCIH states plainly that little is known about whether it's safe to use rhodiola during pregnancy or while breastfeeding, and separately notes a reported interaction between rhodiola and losartan, a blood pressure medicine. 1
2. A review of rhodiola's clinical applications found it can act in an estrogen-like way in some contexts, such as menopause-related research, yet the same review includes no information at all about pregnancy or breastfeeding, reflecting how little this specific question has been studied. 2
3. In a study of pregnant and lactating mice given extracts of Rhodiola kirilowii, a related species, the mothers tolerated it with only modest changes, but offspring showed decreased markers of adaptive immunity and, especially with the hydro-alcoholic extract, possible kidney changes and altered blood vessel development. 3
4. The study's authors concluded that the safety of plant-derived immune-modulating supplements like this one needs to be worked out in further animal research before they're recommended in the maternal diet, not assumed. 3
5. Independent lab testing of commercial rhodiola capsules found rosavin levels running up to five times lower than what the label declared, one product with an undisclosed synthetic ingredient, and trace arsenic, cobalt, and lead in every product tested, a quality-control concern layered on top of the unresolved pregnancy safety question. 4

Is rhodiola safe in each trimester?

• First trimester. Little research exists on rhodiola at any stage of pregnancy, and the one dedicated pregnancy-focused animal study available looked at effects across the full pregnancy and into nursing, not a single trimester.
• Second trimester. There's no second-trimester-specific human or animal data to point to either way, so the same caution that applies earlier in pregnancy continues to apply here.
• Third trimester. Heading into the third trimester, an unregulated supplement market adds another layer of uncertainty: independent testing of commercial rhodiola capsules has turned up inconsistent potency and trace heavy metals, on top of the unresolved pregnancy safety question.