[Yakkal's 3-Point Summary💊]

Vitamin A is fat-soluble and doesn't dissolve in water, so excess amounts can't be excreted in urine and continue accumulating in the liver. Taking high doses daily causes the warehouse in our liver to fill up and overflow.
If you take it carelessly for over a month, your body may send signals: persistent headaches that won't subside, dry eyes that artificial tears can't relieve, and hair loss every time you brush.
Those already taking acne medication (isotretinoin) or high-dose multivitamins, and those planning pregnancy, are at particularly high risk. For pregnancy planning, stop at least 3 months in advanceis safe.

Hello, this is Yakkal's Hu.

In the previous article, oral retinol I explained why it causes no irritation. Because it doesn't touch the skin directly and is slowly delivered through the liver in only the necessary amounts, the skin doesn't become sore or flake like it might with topical creams. But the very fact that you feel nothing can sometimes be the most dangerous warning sign.

A customer came to my pharmacy once. For two months, her head felt heavy, her eyes felt gritty like sand rolling around, and her hair was falling out noticeably. When I asked about all the supplements she was taking, she was taking a multivitamin plus two oral retinol sticks daily. She said she thought it was fine because she didn't feel anything wrong in her body.

Today, I'll honestly explore the shadow hidden behind that silence.

Why Does Vitamin A Accumulate in Your Body? â The Warehouse Called the Liver That Can't Be Emptied

Vitamin C or B taken when tired aren't a major concern even in large amounts. They dissolve well in water, water-soluble so excess amounts are cleanly excreted through urine.

But the core of oral retinol, vitamin A,is the opposite. It only dissolves in oil, fat-soluble. Once it enters, it can't exit through urine and steadily accumulates in the liver.

Simply put, if vitamin C is a sandcastle that dissolves smoothly in water, vitamin A is greasy clay that doesn't come off once it sticks. This clay accumulates in corners of the liver, our body's safe warehouse. The warehouse is fine when spacious, but if you pour in high doses daily just because it's trendy, the storage cabinet will fill up at some point.

When the warehouse door can no longer hold and opens, excess vitamin A overflows through blood vessels throughout the body and begins irritating cells. This is chronic vitamin A toxicity,the starting point, and from this moment, your body turns on its warning lights.

Retinol: 3 Warning Signs Your Body Sends If You Take It Carelessly for Over a Month

When your liver warehouse overflows, your body cries out with three clear signals.

1. Persistent headaches that even painkillers can't relieve

Excess vitamin A blocks the path where cerebrospinal fluid, the clear fluid surrounding the brain, drains. When the fluid pathway in the head becomes blocked, pressure builds up, and this is called pseudotumor cerebri It's not a real tumor, but it means similar symptoms develop due to pressure.

That's why chronic headaches persistâthe head feels full and throbbingâeven when you take Tylenol.

2. Dry eyes and chapped lips that artificial tears can't relieve

Excess retinol excessively stimulates the tear glands, oil glands, and epithelial cells that protect the skin surface, drying them out. The cells that should create moisture become exhausted and can't produce oil or water.

Even applying artificial tears all day long, your eyes feel like sand is rolling around, and your lips and face crack like parched farmland with white flaking skin.

3. Hair loss every time you brush

Hair follicles have a schedule too. Hair density is maintained when the growth phase and rest phase are consistent. But excess retinol accelerates this clock too quickly, forcibly pushing hair that should be growing into a rest phase. That's why hair falls out limply when you wash or brush it.

If these three signals overlap, you need to check the total amount of vitamin A coming from the retinol you're taking. If you're concerned about excess, beta-caroteneâwhich your body converts to vitamin A only as neededâis safer. How to choose safely based on form, dosage, and absorption rate is detailed in ["Vitamin A: Why Choosing Wrong Can Be Toxic"]!

Three pharmacists reviewed this again

I didn't judge this alone either. I reviewed it with three colleague pharmacists from different fields.

Clinical Pharmacist Kim â Fat-soluble compounds are not excreted

The recommended daily amount of vitamin A for adults is 700~900μg RAE, the safe upper limit is 3,000μg RAE(approximately 10,000 IU. If you keep taking amounts close to the upper limit, thinking it will naturally be excreted like water-soluble vitamins, hepatic cumulative toxicity begins. That's why even a trendy beauty powder stick must be checked against the daily upper limit standard.

Dermatology Prescription Pharmacist Lee â Never together with acne medication

The active ingredient in medications like Isotinon and Zerocutan prescribed by dermatologists for severe acne is isotretinoin It's already a medication filling your body with vitamin A derivatives. If you add oral retinol on top of this, liver values (ASTÂ·ALT) spike and systemic dryness worsens. Pharmacies consider this combination contraindicated.

Maternal & Pediatric Pharmacist Park â Pregnancy planning is 3 months, not 1 month

High-dose vitamin A is a potent risk factor that can cause fetal malformations. People often see the 1-month contraception guidelines for dermatology medications and think nutritional retinol is also good for 1 month, but retinyl palmitate in supplements is fat-soluble and remains long in the liver and fat.

If you're planning a baby, it's safe to stop oral retinol and high-dose vitamin A at least 3 months in advance and clear out residual amounts in your body. During this time, it's also helpful to check other nutrients to take alongside, like folic acid. Reading ["Folic Acid Vanishing with a Drink? â Folic Acid Supplementation Precautions"]which covers alcohol and drug interactions, will be helpful!

Check Your Medicine Pouch Now! â High-Risk Group Mapping

If any of the following applies to you, you should stop or avoid retinol sticks no matter how trendy they are.

High-Risk Group 1 â Taking isotretinoin acne medication from dermatology. This medication itself is a high-dose vitamin A derivative. Adding retinol thinking it will clear up faster causes liver values to spike and can result in chapped, bleeding lips or clumps of hair falling out.

High-Risk Group 2 â Already taking high-dose multivitamins or fatigue recovery supplements. Looking at the back of multivitamins, vitamin A often contains 1,500 IU to over 5,000 IU. If you add two to three retinol sticks daily on top of this, you easily exceed the safe upper limit of 10,000 IU.

Retinol Safety Standards at a Glance

Classification	Safety Standard	Signals When Exceeded	Should Not Take Together With
Daily Recommended Amount	Adults 700â900Î¼g RAE	Persistent heavy headaches	Isotretinoin acne medication
Safe Upper Limit	Daily 3,000Î¼g RAE (10,000 IU))	Dry eyes that artificial tears can't relieve	Vitamin A-containing high-dose multivitamins
Pregnancy Planning	Stop at least 3 months in advance	Lip and skin flaking & dryness	Frequent alcohol use and liver-burdening medications
Fetal Risk	High-dose malformation risk	Hair loss when brushing	Hand eczema medication (alitretinoin))

Retinol: You Don't Need to Be Too Afraid

If you've gotten scared reading this far, let me clarify one thing. Yakkal dislikes marketing that simply instills fear. From now on, knowing the standards and correcting course, your body will naturally recover and return to its original state.

That's why in the next article, I won't end by simply saying not to take it. We'll directly flip the back of your current supplement, check together how many Î¼g RAE of vitamin A it contains, and within the safe daily upper limit set by a pharmacist, practical usage methods to get skin benefits without side effects — Whether to choose retinol or beta-carotene, when to take it for better absorption, how to pair it with collagen or vitamin C â I'll explain honestly.

Before then, if the vitamin A numbers on the label are confusing when listed in IU, learning how to convert those numbers to the safe standard Î¼g RAE from ["Supplement IUÂ·RAE Unit Guide"]in advance will make understanding the next article much easier.

I'll return next time with even more reassuring information. Yakkal's Hu, your honest health guide! 😉