How Vitamin B3 and C Interact on the Skin
By a Deadskin scientist still early in his journey, curious enough to keep asking, and honest enough to say when data evolves
For years, a warning has circulated in skincare communities: "Never mix niacinamide (Vitamin B3) and vitamin C."
The concern? That these two ingredients would interfere with each other—making your skincare routine less effective or potentially irritating your skin.
But science keeps moving forward. As new research emerges, it's time to revisit this old rule and ask: Can these two vitamins actually work together to benefit your skin?
Let's break down the science in plain terms.
What Are These Vitamins, Exactly?
Before we talk about combining them, let's understand what each one does for your skin.
Niacinamide (Vitamin B3)
Think of niacinamide as your skin's supportive friend. It:
- Strengthens your skin's protective barrier (like reinforcing your skin's natural shield)
- Reduces redness and irritation (acts as a calming agent)
- Controls oil production (helps balance how much oil your skin makes)
- Evens out skin tone and reduces the appearance of fine lines
Niacinamide dissolves in water and is very stable, meaning it doesn't break down easily in skincare products.
Vitamin C (Ascorbic Acid)
Vitamin C is like your skin's bodyguard and repair crew rolled into one. It:
- Brightens your complexion (gives you that healthy glow)
- Fights environmental damage from things like pollution and sun exposure
- Helps your skin make collagen (the protein that keeps skin firm and youthful)
- Fades dark spots and uneven pigmentation
However, vitamin C is quite fragile—it breaks down when exposed to light, heat, and air. It also works best in an acidic environment (low pH).
This difference in their preferred environments is where the conflict supposedly begins.
Why People Thought They Shouldn't Be Mixed
The warning against mixing these vitamins comes from old laboratory studies from the 1960s. Researchers found that when pure niacinamide and pure vitamin C were combined under high heat for long periods, they formed a compound called niacin.
Niacin can cause "flushing"—temporary redness and a warm, tingling sensation on your skin.
But here's the important part: Those laboratory conditions don't match how modern skincare products are made or used. The studies involved:
- Much less refined ingredients than what's used today
- Extreme heat and prolonged exposure that doesn't happen in real skincare use
- Pure compounds, not the carefully balanced formulations we use now
Despite this, the warning persisted and continues to be repeated today, even by skincare influencers.
What Does Current Research Tell Us?
Modern studies and cosmetic chemists now suggest:
- The combination is safe and can be beneficial when properly formulated
- No significant niacin formation occurs under normal skincare conditions
- Many current products successfully combine both ingredients with good results
Recent peer-reviewed research has found that combining antioxidants like vitamin C and B3 actually provides better protection against environmental damage than using either one alone.
Even companies known for their scientific approach to skincare, like The Ordinary, now sell products containing both ingredients without any warnings.
What Actually Happens on Your Skin?
When these vitamins are properly combined:
- Vitamin C acts as your defender, brightening skin and fighting environmental damage
- Niacinamide acts as your supporter, soothing irritation and strengthening your skin's barrier
- Together, they complement each other—vitamin C handles external threats while niacinamide maintains internal skin health
Your skin isn't a laboratory test tube. It's a living, dynamic system that responds differently than isolated ingredients in a lab. What matters most is how products are formulated, not just the individual ingredient names.
How to Use Them Together (If Using Separate Products)
If you're using products that contain these vitamins separately and want to be extra cautious:
- Apply vitamin C first in the morning (it's more sensitive to pH and works best on clean skin)
- Wait 5-10 minutes for absorption
- Follow with your niacinamide product (serum or moisturizer)
This approach ensures proper absorption and avoids any theoretical pH conflicts. However, this precaution is optional, not required.
Can You Use Them If You Have Sensitive Skin?
Yes, but start slowly:
- Begin using them together 2-3 times per week
- Avoid high concentrations of both until you know how your skin responds
- Test on a small area first if you're concerned about reactions
Some people may react to vitamin C's acidity rather than the combination itself. Others find the pairing works better when buffered with a hydrating serum or moisturizer.
What We Do at Deadskin
Our future formulations are based on current science, not outdated assumptions. If we include both niacinamide and vitamin C, it's because we've:
- Verified their stability together
- Tested the results
- Ensured the final product feels good on skin
We follow evidence, not myths. We believe in understanding how molecules work—and listening to the people who test them.
The Bottom Line
Can you use vitamin B3 and C together? Yes. And in many cases, you probably should.
Not because it's trendy, but because current research suggests they can protect, strengthen, and brighten your skin more effectively together than separately.
Skincare isn't just about avoiding irritation—it's about creating routines that make sense and deliver results.
As science evolves, so does Deadskin. We're always learning and willing to update our understanding when new evidence emerges, especially when it means better results for your skin.
The old rule against mixing these vitamins was based on outdated information. Today's evidence suggests they can work beautifully together—giving you the best of both worlds.