Beauty Davines OI Oil vs OI All in One Milk: Which to Buy First
Davines OI Oil and OI All in One Milk are the two heroes of the OI line. The oil is a concentrated shine finisher. The milk is a lightweight detangling leave-in. Here is how they compare.
| Factor | Davines OI Oil Absolute Beautifying Poti | Davines OI All in One Milk, 4.56 fl oz |
|---|---|---|
| Format | Concentrated oil | Light leave-in milk |
| Main benefit | Shine and frizz control | Detangling and softness |
| Best step | Finishing on dry hair | Damp hair before styling |
| Fine hair fit | Good in tiny amounts | Excellent, weightless |
| Thick hair fit | Excellent | Good, may need oil too |
| Scent | Stronger, lasting | Softer version |
| First buy | Iconic hero product | Easier daily use |
Our Verdict
Choose the OI Oil first if shine and luxury are your goals. It is the iconic product that built the line's fame. Choose the All in One Milk first if you want an easy daily detangler, especially for fine hair. Most devotees end up owning both. Start with the one matching your biggest need.
More Top Picks in This Category
Not sold on either of these two? Here are more bestselling options worth considering.
Best for: Trying OI Oil or traveling.
Davines OI Oil Absolute Beautifying Potion, 1.69 fl oz
- Travel size OI Oil
- Same luxury formula
- Try size
- TSA friendly
Pros
- Try before full size
- Perfect for travel
- Lower commitment
Cons
- High per ounce cost
- Empties fast
- Tiny bottle
Best for: Sampling the milk or travel use.
Davines OI All in One Milk, 1.69 fl oz
- Travel milk size
- Same detangling power
- Try size
- Compact
Pros
- Good trial size
- Travel friendly
- Same quality
Cons
- Pricey per ounce
- Small for long hair
- Runs out quickly
Best for: The OI routine foundation cleanse.
Davines OI Shampoo, 9.47 fl oz
- Gentle OI shampoo
- Softening cleanse
- All hair types
- Rich lather
Pros
- Luxurious wash
- Hair feels soft
- Preps for OI styling
Cons
- Premium shampoo price
- Needs conditioner after
- Scent strong for some
Want the Full Picture?
Layering Order: Milk, Style, Oil
The OI Oil and All in One Milk have a designed sequence that the comparison implies but never states outright. The Milk goes first on damp hair: its lightweight detangling formula primes the hair and provides the slip for styling. Styling products come next. The Oil goes last, on dry or nearly-dry hair, sealing everything with shine. Reversing the order, oil before milk, traps the milk's conditioning agents under an oil barrier and mutes both.
The full stack: milk on damp hair, heat protectant if needed, styling cream or mousse, then a tiny amount of oil pressed onto dry ends as the finisher. Watch for pilling where the oil meets water-based gels; if flakes appear, simplify the styler to a cream. On non-wash days, the oil alone refreshes ends without disturbing the milk base from wash day. The travel-size oil in the recommended products is ideal for learning the dose without committing to the full bottle. For the luxury oil comparison, our Kerastase Elixir Ultime comparison covers the other iconic shine oil.
Dosing the OI Oil: Tiny Amounts, Big Results
The comparison notes the oil works for fine hair "in tiny amounts," and that qualifier carries the whole technique. The OI Oil is concentrated; one pump is plenty for medium hair, half a pump for fine hair. Warm it between palms until it nearly disappears, then press onto the mid-lengths and ends of dry hair. On damp hair, use slightly more, since water aids distribution.
The over-application rescue: blot with a dry microfiber towel rather than rewashing, which lifts excess while keeping the shine layer. The Milk needs no such discipline; its weightless formula is genuinely hard to overdo, which is why fine-haired buyers should start there. The common mistake is treating the oil like the milk: generous, casual application. Treat the oil like perfume, measured and deliberate, and the milk like moisturizer, generous and easy. For repair-focused alternatives, our best hair serum for damaged hair guide covers five treatment serums.
Storing the OI Line for Freshness
Davines' naturally-derived formulas deserve the same storage discipline as any prestige oil. Heat, light, and air oxidize the oils; the OI Oil's larger bottle, opened daily, ages gradually from the first pump. Store in a cool, dark cabinet, never on a sunny vanity, with the cap closed between uses.
Signs of decline: the signature scent turns sharp or flat, the texture thickens, or absorption slows. The travel size is the freshness-smart choice for infrequent users; a full bottle that takes eighteen months to finish spends its last six months past prime. Most oils stay prime 12 to 24 months after opening; write the open date on the base. The Milk's lighter formula is slightly more vulnerable to heat, so keep it out of hot bathrooms. Buy the size you will finish within a year and every drop performs.
The OI line's cult status rests on the combination this guide has mapped: the Milk's effortless daily care plus the Oil's concentrated finishing luxury. Respect the layering order, dose the oil with discipline, store both properly, and the duo delivers the shine and softness that built the line's fame. Two products, one routine, zero guesswork.