Niacinamide vs Vitamin C: Which Should You Use in Your DIY Serum?

Deciding between niacinamide vs vitamin C serum for your next DIY project can feel like choosing between two superstar ingredients. Both are renowned for their ability to brighten, protect, and rejuvenate the skin, but they work in fundamentally different ways. Whether you are looking to tackle stubborn hyperpigmentation or simply want to strengthen your skin barrier, understanding how these actives interact with your unique skin type is the first step toward creating a professional-grade formulation at home.

In the world of DIY skincare, the niacinamide vs vitamin C serum debate often comes down to stability and pH requirements. While many commercial products claim to offer the best of both worlds, home formulators need to be mindful of how these ingredients behave when mixed in a water-based solution. In this guide, we will break down the science behind both actives, explore their individual benefits, and help you decide which one deserves a spot in your skincare laboratory today.

What Is Niacinamide?

Niacinamide, also known as Vitamin B3, is a water-soluble vitamin that has become a staple in modern skincare for its versatility and gentle nature. Unlike some high-intensity actives that can cause irritation, niacinamide is generally well-tolerated by all skin types, including sensitive and acne-prone skin. It is a precursor to two essential co-enzymes in your cells (NAD and NADP) which play a crucial role in cellular repair and energy metabolism.

For the home formulator, niacinamide is a dream to work with. It is highly stable, heat-resistant, and performs best at a neutral pH of around 6.0. This makes it much easier to incorporate into various DIY recipes compared to more temperamental ingredients. Whether you are building a simple hydrating toner or a complex anti-ageing serum, niacinamide provides a reliable foundation for skin health without the constant worry of oxidation or degradation.

What Is Vitamin C?

Vitamin C is perhaps the most famous antioxidant in the skincare world, primarily known in its pure form as L-ascorbic acid. It is a powerhouse ingredient that neutralises free radicals caused by UV exposure and pollution, effectively acting as a shield for your skin cells. Beyond protection, it is essential for the synthesis of collagen, the protein responsible for keeping our skin firm, plump, and youthful.

However, Vitamin C is notoriously difficult to formulate in a DIY setting. L-ascorbic acid is highly unstable; it oxidises quickly when exposed to light, air, or heat, turning a tell-tale orange-brown colour that indicates it has lost its potency. Furthermore, it requires a very low (acidic) pH of approximately 3.0 to 3.5 to effectively penetrate the skin barrier. This acidic environment can be irritating for beginners or those with sensitive skin, which is why many DIYers opt for more stable Vitamin C derivatives like Sodium Ascorbyl Phosphate or Magnesium Ascorbyl Phosphate.

Benefits of Niacinamide for Skin

• Strengthens the Skin Barrier: Niacinamide boosts the production of ceramides, the lipids that help maintain the skin’s protective layer and lock in moisture.
• Regulates Oil Production: It helps balance sebum activity, making it an excellent choice for those with oily or combination skin who want to reduce shine.
• Reduces Redness and Inflammation: Its anti-inflammatory properties help calm irritated skin and reduce the appearance of blotchiness or rosacea.
• Minimises Pore Appearance: By keeping the skin smooth and clear of excess oil, it helps pores look smaller and more refined over time.
• Fades Hyperpigmentation: It inhibits the transfer of pigment (melanin) to skin cells, helping to even out skin tone and fade dark spots.

Benefits of Vitamin C for Skin

• Potent Antioxidant Protection: It neutralises free radicals, preventing the oxidative stress that leads to premature ageing and fine lines.
• Brightens Dull Complexion: Vitamin C interferes with the enzyme tyrosinase, which produces melanin, leading to a noticeably brighter and more radiant skin tone.
• Boosts Collagen Synthesis: It is a vital co-factor for the enzymes that stabilise and cross-link collagen fibres, improving skin elasticity.
• Enhances Sunscreen Efficacy: When worn under SPF, Vitamin C provides an extra layer of protection against the UV rays that manage to bypass your sunscreen.
• Fades Acne Marks: It helps speed up the skin’s natural healing process, making it effective at reducing post-inflammatory hyperpigmentation (PIH).

Niacinamide vs Vitamin C: Can You Use Them Together?

A common myth in the skincare community is that you cannot use niacinamide and Vitamin C together because they “cancel each other out.” This idea stems from older research suggesting that at high temperatures and low pH, niacinamide can convert into nicotinic acid, which causes temporary skin flushing. However, in modern formulations and at room temperature, this conversion is minimal and generally not a concern for most users.

The real challenge for the DIY formulator is the pH conflict. L-ascorbic acid needs a pH of 3.5 to work, while niacinamide is happiest at pH 6.0. If you try to force them into the same water-based serum, you will likely end up with a product that is either too acidic for the niacinamide (causing flushing) or too alkaline for the Vitamin C (causing it to oxidise). To get the best of both worlds in your DIY routine, we recommend using your Vitamin C serum in the morning for antioxidant protection and your niacinamide serum in the evening for barrier repair.

What You Need for a DIY Brightening Niacinamide Serum

If you are a beginner, starting with a niacinamide serum is highly recommended due to its stability. Here is what you will need to create a professional, effective 5% Niacinamide serum at home:

• Distilled Water (84%): The base of your serum. Never use tap water as it contains minerals that can destabilise your actives.
• Niacinamide Powder (5%): The star active ingredient for barrier support and brightening.
• Vegetable Glycerin (5%): A humectant that helps draw moisture into the skin and gives the serum a nice “slip”.
• Hyaluronic Acid Powder (1%): For intense hydration and a luxurious, slightly thickened texture.
• Liquid Germall Plus (0.5%): A broad-spectrum preservative to keep your serum safe from bacteria and mould.
• Panthenol / Pro-Vitamin B5 (4.5%): A soothing additive that works synergistically with niacinamide to repair the skin.

Step-by-Step Recipe: How to Make Your Serum

1. Sanitise Everything: Before you begin, thoroughly clean your workspace and all equipment (beakers, stirrers, bottles) with 70% isopropyl alcohol.
2. Mix the Water and Glycerin: In a heat-safe glass beaker, combine your distilled water and vegetable glycerin. Stir until well combined.
3. Hydrate the Hyaluronic Acid: Sprinkle the hyaluronic acid powder over the water surface. Do not stir immediately; let it sit for 30–60 minutes until it forms a clear gel. Stir gently to remove any remaining clumps.
4. Add the Actives: Once the gel is smooth, add the niacinamide powder and panthenol. Stir until the powder is completely dissolved and the liquid is clear.
5. Check and Adjust pH: Use a digital pH meter or high-quality pH strips. The serum should be around pH 6.0. If it is too low, add a drop of 10% sodium hydroxide solution; if too high, add a drop of 10% citric acid solution.
6. Add the Preservative: Once the pH is correct and the serum is at room temperature, stir in the Liquid Germall Plus.
7. Bottle and Label: Pour your finished serum into a clean, dark glass dropper bottle. Label it with the name and the date you made it.

Tips for Best Results

• Use Fresh Ingredients: Always source your raw materials from reputable Australian suppliers to ensure potency and purity.
• Store Correctly: Even though niacinamide is stable, keep your serum in a cool, dark place to extend the shelf life of the other ingredients like panthenol.
• Be Patient with Results: Like all skincare, consistency is key. Use your serum daily for at least 4–6 weeks to see a noticeable difference in skin texture and tone.
• Master the Basics First: If you really want to use Vitamin C, consider starting with a stable derivative like Sodium Ascorbyl Phosphate before attempting a complex L-ascorbic acid formulation.

Safety and Patch Testing

Even though niacinamide is generally very safe, every individual’s skin is different. Before applying your new DIY serum to your entire face, perform a patch test. Apply a small amount of the product to the inside of your forearm or behind your ear and wait 24 hours. If you experience any redness, itching, or burning, discontinue use immediately. Always ensure your formulations are properly preserved to prevent microbial growth, which can lead to skin infections.

Frequently Asked Questions

Can I mix Vitamin C powder directly into my niacinamide serum?
It is not recommended. As discussed, the pH requirements for L-ascorbic acid and niacinamide are very different. Mixing them directly can lead to skin irritation or make the Vitamin C ineffective. It is better to formulate them as two separate serums or use a stable Vitamin C derivative.

How long will my DIY niacinamide serum last?
When formulated with a broad-spectrum preservative like Liquid Germall Plus and stored in a cool, dark place, your serum should remain safe and effective for 3 to 6 months. Always check for changes in smell, colour, or texture, and discard if anything looks “off”.

Is a 10% niacinamide serum better than 5%?
Not necessarily. Research shows that 2% to 5% niacinamide is highly effective for most skin concerns. While 10% is popular in commercial products, it can be slightly more irritating for sensitive skin types without offering significantly better results for everyone. 5% is the “sweet spot” for most DIYers.

Conclusion

Choosing between niacinamide vs vitamin C serum doesn’t have to be an “either-or” decision, but for the home formulator, it is often a matter of which one to master first. Niacinamide offers a stable, beginner-friendly entry into the world of active serums, providing incredible barrier-boosting and anti-inflammatory benefits with very little risk. Once you have perfected your niacinamide recipe and feel comfortable with pH testing, you can then venture into the more challenging world of Vitamin C. Ready to start your formulation journey? Grab your beakers, follow our recipe above, and see the difference a custom-made serum can make for your skin!