This is a topic we held off writing about until we could do it carefully. Pregnancy and breastfeeding change the safety calculus on almost everything, including products we sell — and the honest answer for several of them is "talk to your doctor first," not a confident green light. Nothing below is clearance to take anything. Here's what the actual guidance says, product by product.
Caffeine: the numbers that matter
A fact sheet from MotherToBaby, an NIH-affiliated service that reviews medication and supplement safety in pregnancy and breastfeeding, gives specific figures: most experts, drawing on ACOG guidance among others, recommend pregnant women limit caffeine to 200mg or less per day.1 For breastfeeding the same sheet gives a higher ceiling — 300mg or less — since only small amounts pass into breast milk, though newborns clear caffeine far more slowly than adults, so timing relative to feeds matters. Watch for agitation, irritability, trouble sleeping, rapid heart rate or tremor in the baby, and contact their healthcare provider if you see them.
200mg or less per day in pregnancy, 300mg or less while breastfeeding — and that's a total across everything you drink and take that day, not a per-product allowance.
Where the guidelines agree, and where they don't
A 2025 review in Nutrients lays the thresholds side by side. ACOG advises no more than 200mg a day; the European Food Safety Authority concludes habitual intake up to 200mg does not raise safety concerns for the fetus, and the UK Food Standards Agency agrees. The WHO suggests below 300mg; the Government of Canada also allows up to 300mg in pregnancy or breastfeeding.5 They converge on a 200–300mg band, and the review names the downside of that spread: differing recommendations confuse people and invite unintentional overconsumption. If you want one number, 200mg is the conservative end, and the one ACOG uses.
The part most guidance leaves out: caffeine lasts longer in pregnancy
A daily milligram limit quietly assumes your body clears caffeine at its usual rate. In pregnancy it doesn't. CYP1A2 — the liver enzyme responsible for over 95% of caffeine clearance — becomes less active as pregnancy progresses, and caffeine's half-life, normally around 4–5 hours, extends to approximately 15 hours in the late gestational trimester: up to roughly threefold.5
So the same daily intake produces higher circulating levels later in pregnancy — and caffeine and its metabolites cross the placenta, raising fetal catecholamine levels.5 The authors add a point worth acting on: at a half-life over 15 hours, dosing more often than once per half-life lets caffeine accumulate, so spacing matters, not only the daily sum.
What the outcome research actually shows — and where it stops
MotherToBaby is precise about the strength of each finding, and precision is the point.1 No association has been reported between intake under 200mg and increased miscarriage risk; some studies suggest the chance may be increased at 200–300mg or above 300mg. Caffeine has not been shown to increase birth defects. Most studies find no clear evidence that low-to-moderate intake increases preterm delivery or low birth weight — and doses above 300mg are described bluntly as "not well studied." Some reports suggest babies exposed to more than 500mg a day in the third trimester were more likely to have faster heart rates, shaking, faster breathing and more time awake in the days after birth.
The 2025 review names this literature's limitations in its own words: guidelines are population-based and expressed in mg/day rather than personalised clearance, because CYP1A2 activity varies widely by genotype and plasma clearance isn't measured in clinical practice; most cohort studies rely on self-reported intake; and animal studies showing developmental harm used doses far above typical human exposure.5 None of that makes the 200mg advice wrong. It means it's a reasonable population margin, not a measured personal threshold — an argument for staying under it, not for treating it as soft.
Where this gets specific to Cognitive Support
Cognitive Support's caffeine sits inside a 255mg proprietary blend shared with seven other ingredients, and the per-capsule amount is not on the label. We asked our manufacturer for the figure so we could publish it; they confirmed it cannot be published.2
In this context that isn't a technicality, it's decisive. A 200mg ceiling is arithmetic, and you cannot do arithmetic with an unknown. Our guidance: do not take Cognitive Support during pregnancy or while breastfeeding. The only exception we'd recognise is a doctor who has reviewed the full ingredient list and specifically told you otherwise — and they will be working without the caffeine number too.
Sleep Support and Sleep Formula: the melatonin question
Both contain melatonin — 10mg per two-capsule serving in Sleep Support, 2mg in Sleep Formula.
A 2022 scoping review found 15 relevant human studies — eight on pregnancy, seven on breastfeeding. Its conclusion was more reassuring than animal work had implied: melatonin use in pregnancy and breastfeeding is "probably safe in humans."3 Two caveats carry the weight. There were no randomised trials of melatonin's efficacy or safety for sleep problems in pregnancy or lactation, and insomnia was not the primary outcome in any included study — the trials reporting no major safety concerns were giving melatonin for other conditions entirely.
So: not evidence of harm, and not a trial that answers the question you're asking. Melatonin is a hormone, it crosses into breast milk and the placenta, and 10mg nightly is at the high end of what melatonin research generally uses — see why we're cautious about melatonin. Sleep Support also carries a 905mg blend of 14 botanicals whose individual doses aren't disclosed, a second unknown; we break it down in inside Sleep Support. Both products are firmly "discuss with your doctor before use," not a self-directed decision either way. If broken sleep is the actual problem, the non-supplement options have better evidence — see CBT-I.
Creatine Monohydrate: promising, but human safety data is still thin
Creatine Monohydrate has been discontinued from the Proco range — we're keeping this section because the underlying research question is still useful.
Creatine is one of the most well-studied supplements in the general population, but that evidence doesn't transfer automatically to pregnancy. The pregnancy-specific safety research is still largely preclinical — a 2025 study modelling maternal creatine supplementation used a guinea pig model of full-term pregnancy, not human trial data.4 The 2025 review of creatine in women's health says the same from the other direction: the prophylaxis evidence comes from spiny mouse and fetal sheep models, with human dosing and tolerability data still being collected to inform possible trials. We go through that literature, and who funded the review, in creatine and women. Talk to your doctor first.
Omega-3 and Magnesium Glycinate: the more reassuring picture
These two have a comparatively better-established safety profile — omega-3 (EPA/DHA) is commonly recommended in pregnancy for fetal brain and eye development, and magnesium is standard in prenatal nutrition guidance. Neither contains a proprietary blend, so the arithmetic problem above doesn't apply: the serving amounts on the panel are the whole picture. But "well-supported" is not "cleared without discussion" — confirm dosing with your doctor or OB, particularly total intake from prenatal vitamins plus any addition. Our EPA/DHA dosage guide and complete magnesium guide cover what the trials used.
If the underlying problem is brain fog or low mood
People often reach for a supplement here because something genuinely feels wrong, and a stimulant with an undisclosed dose is the worst available answer. Postpartum cognitive change has its own literature — postpartum brain fog — and the trial evidence on omega-3 for postpartum depression, including where it's weak, is in omega-3 and postpartum depression.
The one rule that covers everything on this page
None of this substitutes for a conversation with your own doctor, OB-GYN or midwife. Bring your supplement list — all of it — and the physical labels, because "a focus supplement with caffeine in a blend" is harder to assess than a number.
References
- "Caffeine." MotherToBaby Fact Sheets, updated November 2025; also available via NCBI Bookshelf. mothertobaby.org · ncbi.nlm.nih.gov
- "How Much Caffeine Is Actually in Cognitive Support?" Proco. procohq.com
- Vine T, Brown GM, Frey BN. "Melatonin use during pregnancy and lactation: A scoping review of human studies." Brazilian Journal of Psychiatry, 2022. doi:10.1590/1516-4446-2021-2156. pmc.ncbi.nlm.nih.gov
- "Safety of maternal creatine supplementation: evidence from a guinea pig model of full-term pregnancy." Journal of the International Society of Sports Nutrition, 2025. tandfonline.com
- "Pregnancy and Caffeine Metabolism: Updated Insights and Implications for Maternal-Fetal Health." Nutrients, 2025;17(19). pmc.ncbi.nlm.nih.gov
This article is for informational purposes only and has not been evaluated by the FDA. It is not intended to diagnose, treat, cure, or prevent any disease, and it is not a substitute for medical advice. Always speak with your doctor, OB-GYN, or midwife before starting, continuing, or stopping any supplement during pregnancy or while breastfeeding — bring your full supplement list to that conversation.
Related reading: Does Cognitive Support Contain Caffeine? and Omega-3 and Postpartum Depression: What the Research Actually Shows
Review every label with your doctor at procohq.com before taking anything in pregnancy or while breastfeeding.