Essential Oil Diffuser for TTC & Pregnancy — ASAKUKI 500ml

A diffuser for the long nights, not a fertility treatment

The ASAKUKI 500ml is an ultrasonic diffuser and light humidifier. You fill the tank with water, add a few drops of essential oil, and a 2.4MHz plate breaks it into a fine cool mist. It runs up to 18 hours on the low-mist setting, has 60/120/180-minute timers plus a steady-on mode, seven LED colours that can be fixed or cycled, an intermittent mist mode, and a remote that works from up to 16.5 feet. The mist and the light run independently, so it can be a nightlight with no scent at all, or scent with no light.

We are going to be straightforward about what this is. A diffuser is hardware, and it ships without oils. It does not act on your hormones, your lining or your egg quality, and nothing about scenting a room changes the odds of a cycle working. What it does do is make a room feel different at 2am, and give you something small and repeatable to do on the evenings when there is nothing else to do. That is a real job, and it is the one we sell it for.

How many drops to use in pregnancy — and why the manual says more

Start with one drop. Work up to three to five only if you are comfortable. That is the guidance from Emily Sisco, CNM, a certified nurse-midwife in OB-GYN at Mayo Clinic Health System, writing in March 2024 about aromatherapy in pregnancy.

Now read the instructions that come with this diffuser. ASAKUKI's own directions panel says "2-4 drops per 100ml of water, 5-10 drops for full tank." Two things are worth noticing there.

• Those two numbers disagree with each other. Two to four drops per 100ml, across a 500ml tank, is ten to twenty drops — not the five to ten the same panel gives for a full tank.
• Even the lower figure starts where the midwife's range ends. Five drops is the top of what Mayo suggests working up to, and it is five times her starting point.

This matters more in pregnancy than it would otherwise, because pregnancy sharpens your sense of smell. Mayo notes that aromatherapy can become overwhelming and can itself trigger nausea. Filling a 500ml tank to the manual's spec is a plausible way to end up queasy because of the device you bought to feel better — and once the oil is in the water, you cannot take it back out.

Mayo's other suggestion is worth having even if you own a diffuser: put a drop on a tissue or a cotton ball. If it stops being tolerable, you throw it away. A full tank has to be emptied and rinsed.

One more thing from the same panel, because people get it wrong: this diffuser requires water. Neat oil in the tank will damage it.

Why women love it

• Runs 18 hours on low mist: covers a full night and then some, on one 500ml tank
• Mist and light work separately: scent with the room dark, or a soft nightlight with no scent — useful when your tolerance for smell changes week to week
• Timers you can set from bed: 60, 120 and 180 minutes, plus intermittent mist, all on a remote that reaches 16.5 feet
• Quiet enough to sleep beside: ASAKUKI's own lab rates the fan under 23 dB; in practice, reviewers overwhelmingly buy it as a bedroom device
• Auto shut-off when the water runs out: the safety feature that matters if you are going to fall asleep with it on
• Doubles as a light humidifier: genuinely helpful for a dry winter bedroom or a stuffy nose. It does not clean or purify the air — see the FAQ
• Small and light: 6.62 in wide, 4.15 in tall, 0.86 lb, so it moves from bedside to desk without ceremony

Best for

• Women who want a wind-down ritual through the two-week wait or an IVF cycle, and want it sold to them honestly
• Anyone whose sleep has gone sideways and who wants a nightlight and a timer more than they want aromatherapy
• Pregnant women looking for a way to use essential oils at the lowest-exposure end — inhaled and dilute, rather than on skin or swallowed
• Dry winter bedrooms where a little added humidity helps a blocked nose
• Gifting: it arrives in a gift box, and it is a kinder gift for someone in a hard season than anything that implies she should be doing more
• Not for an infant's nursery, a home with birds, or a pet with a history of breathing problems — details in the FAQs below

Related reading

If the reason you are looking at a diffuser is that the waiting has got heavy, start with Mindy's guide to whether stress affects fertility, what the science actually says, and how to cope — it covers the question this product tends to be bought for, and the answer is more reassuring than most people expect. If you are heading into a cycle, how to prepare for IVF walks through the body, mind and logistics side of it.

Explore more

This diffuser sits in our emotional support for the TTC journey collection, alongside the rest of what Mindy has curated for the waiting rather than the trying. The broader fertility essentials for TTC collection covers tracking, supplements and testing.

A quiet companion for the wait

A diffuser gives you something to switch on. An affirmation candle gives you something to read while you do. Ours are made for exactly the seasons this product gets bought in — the month after a negative test, the week before a transfer — and they say out loud the thing a diffuser only gestures at: that the waiting is hard, and that you are allowed to take care of yourself inside it.

A note from Mindy

I want to say something specific about why I am comfortable recommending this, because I am not comfortable with how most things in this category are sold.

The pitch is almost always some version of lower your stress and you will conceive. It is worth knowing that this has been studied directly. A 2011 meta-analysis in the BMJ by Boivin and colleagues pooled fourteen prospective studies covering 3,583 women starting a cycle of assisted reproduction, and found that anxiety and depression before treatment were not associated with whether the treatment worked. The authors' own conclusion was that emotional distress — whether it comes from the fertility problem itself or from everything else happening in your life at the same time — does not compromise your chance of becoming pregnant.

I think about that finding a lot, because the women I see in clinic have usually been told some version of "just relax" by someone who meant well, and have quietly concluded that their own distress is part of why this is not working. It is not. You did not cause this by being stressed about it.

So buy the diffuser if it will make your evenings better. Buy it because you sleep badly and a timer and a soft light help, or because switching it on is a way of marking that the day is over. Those are good reasons. Just do not buy it as a treatment, and please do not let anyone — including a product page — imply that your stress is the thing standing between you and a baby.

One clinical caution while I have you. Essential oils are not regulated by the FDA and the safety research is genuinely thin, so "natural" is not doing the work people think it is. Do not ingest them during pregnancy or breastfeeding, do not put them on your skin undiluted, and if a particular oil is one you are unsure about, ask your own provider about that specific oil rather than trusting a list you found online. Mine included.

— Mindy Motta, FNP-C

Frequently asked questions

Is it safe to diffuse essential oils while pregnant?

Inhaling a dilute, diffused oil is the lowest-exposure way to use essential oils, and Mayo Clinic Health System's guidance describes aromatherapy as something pregnant women can try, with caution. The firmer rules are the other routes: do not swallow essential oils during pregnancy or breastfeeding, and do not apply them undiluted to skin. Research on aromatherapy is limited overall, so discuss it with your own provider, especially in the first trimester.

How many drops of essential oil should you use in a diffuser during pregnancy?

Mayo Clinic Health System's nurse-midwife guidance is to start with one drop and increase to three to five based on your tolerance. That is notably less than this diffuser's own instructions, which say five to ten drops for a full tank — and elsewhere on the same panel, two to four drops per 100ml, which works out to ten to twenty. Start at one. Pregnancy heightens your sense of smell, and too much can trigger nausea.

Which essential oils are safe to diffuse in pregnancy?

Mayo's OB-GYN guidance names a few with some evidence behind them: peppermint for headaches, nausea and congestion, and lavender and rose, which have been found to reduce anxiety in labour. Beyond that, published lists of oils to avoid vary widely and are not backed by strong evidence in either direction, so we are not going to print one. Ask your provider about the specific oil you are considering.

Can essential oils help you get pregnant?

No. There is no good evidence that any essential oil improves fertility, and this diffuser does not ship with oils in any case. It is also worth knowing that a 2011 BMJ meta-analysis of 14 studies in 3,583 women found emotional distress before fertility treatment was not associated with whether the treatment worked — so the underlying premise, that calming down will improve your odds, does not hold either. Buy it to sleep better, not to conceive faster.

Is it safe to use an essential oil diffuser in a baby's nursery?

We would not. Amazon lists "Nursery" among this product's recommended uses and ASAKUKI's packaging says the BPA-free plastic is safe for babies — but that is a statement about the housing, not about diffusing oils around an infant. Johns Hopkins All Children's pediatric guidance notes that children are more likely than adults to react badly to essential oils, with reported coughing, wheezing and allergic reactions, and that peppermint oil specifically should not be used around children under 30 months because it can increase seizure risk. Use it in your own room, not the baby's.

Is an essential oil diffuser safe around cats, dogs and birds?

The ASPCA Animal Poison Control Center's position is that running a diffuser for a short period in a secured area your pet cannot reach is not likely to be a problem. Two exceptions they name directly: avoid a diffuser altogether if your pet has any history of breathing problems, and avoid using one anywhere in the house if you keep birds, whose respiratory tracts are very sensitive. Keep concentrated oils out of reach — the ASPCA notes tea tree oil can cause problems at seven or eight drops — and site the diffuser where it cannot be knocked over.

Can you run this diffuser without essential oils, as a humidifier?

Yes, and plenty of people do. Filled with plain water it works as a small cool-mist humidifier with a nightlight, which is useful for a dry bedroom or a stuffy nose. What it will not do is purify or clean the air. The American Academy of Pediatrics is explicit that scented products do not improve air quality and can add chemicals to it, so treat any "purifying" language on diffusers — this one included — as marketing.

How long does the ASAKUKI 500ml diffuser run on one tank?

Up to 18 hours on the low-mist setting from a full 500ml tank, less on high. There are 60, 120 and 180-minute timers plus a steady-on mode, and an intermittent setting that alternates misting and resting to stretch a tank further. It shuts itself off automatically when the water runs out.