Single-oil monograph
Grapefruit (Citrus x paradisi, cold-pressed)
- Phototoxic Dose-dependent phototoxicity
- Pregnancy Caution
- Pets Avoid
Published 2026-09-28 · adult ceiling 2% · shelf life 18 months
Grapefruit is phototoxic at roughly a third of bergamot's severity — which is still phototoxic. It is also 90% limonene, which makes it the second-fastest-oxidising oil on this site, and it is the oil most often used in daily body blends applied before people go outdoors. The combination is why this site prints a 2% adult ceiling and a 0.5% figure for anything that will see daylight.
Safe dilution matrix
Rows are the concentration, columns are the audience. Each cell carries two lines: drops per 10 ml of carrier oil, and whether this site advises that combination. Figures come from 1 ml = 20 drops, and the bold row is the ceiling for this oil.
| Dilution | Per 30 ml | Adult | Child 6+ | Pregnancy | Pets |
|---|---|---|---|---|---|
| 0.5% | 3 | 1 drops ✓ advised | 1 drops ✓ advised | 1 drops ✗ not advised | 1 drops ✗ not advised |
| 1% | 6 | 2 drops ✓ advised | 2 drops ✓ advised | 2 drops ✗ not advised | 2 drops ✗ not advised |
| 2% | 12 | 4 drops ✓ advised | 4 drops ✗ not advised | 4 drops ✗ not advised | 4 drops ✗ not advised |
What each concentration is normally for: 0.5% — Facial blends, sensitive or broken skin, children 6-15, first patch test · 1% — Everyday adult body and massage blends, daily leave-on use · 2% — Short-term localised adult use, 7 to 10 days then re-assess · 3% — Adult ceiling for robust oils, small area, short course only
Contraindications & handling
✓ no restriction · ! caution · ✗ avoid. An avoid row means choosing a different material, not lowering the concentration.
- ! Pregnancy & breastfeeding — caution
- ! Children under 16 — caution
- ✗ Households with pets — avoid
- ✓ Epilepsy — ok
- ! Antihypertensive medication — caution
- ✓ Anticoagulant medication — ok
Four-step skin patch test
- Dilute 1 drop in 5 ml of carrier oil (1%). Never patch test expressed grapefruit neat.
- Apply 2 drops to the inner forearm and let it dry.
- Cover for 24 hours and keep the arm out of the sun for 48 hours.
- Read at 24 and 48 hours. Grapefruit is a weaker phototoxin than bergamot but it is a phototoxin; treat any second-day reaction as decisive.
Botanical record
- Family
- Rutaceae · Rutaceae
- Botanical part
- peel
- Extraction
- cold-pressing
- Origin
- United States (Florida, Texas), Israel, Argentina, South Africa
- Chemotype
- Limonene-dominant with nootkatone trace
- Phototoxicity
- Dose-dependent phototoxicity
- Shelf life
- 18 months
Principal constituents
- Limonene 90%
- Myrcene 3%
- alpha-Pinene 0.8%
- Sabinene 0.6%
- Nootkatone 0.2%
- Oxypeucedanin 0.1%
Storage & oxidation
At 90% limonene, grapefruit oxidises about as fast as sweet orange and rather faster than lemon, and its phototoxic furanocoumarin content is unaffected by ageing. That is an awkward combination: the safety margin narrows from two directions at once. Eighteen months maximum, twelve for a bottle that is half empty.
Rotation & substitution
Grapefruit is one of the oils most often used in "cellulite" and "detox" body blends that are applied daily before going outside, which is close to the worst possible pattern for it. If you use it on the body, use it in the evening, keep the concentration at or below 1%, and rotate it out after two weeks.
Adjacent materials
Sweet orange (Citrus sinensis) · monograph
Not phototoxic
Grapefruit
Steam distillation removes the oxypeucedanin and the phototoxicity with it