How much protein is in grapefruit?
Grapefruit has 1 g of protein per 1/2 medium (123 g) — that's 0.8 g per 100 g, or about 0.2 g per ounce. One 1/2 medium is roughly 2% of the 50 g Daily Value for protein.
USDA FoodData Central · raw · FDC 174673
Protein & macros by portion
| Portion | Protein | Calories | Fat | Carbs |
|---|---|---|---|---|
| 1/2 medium (123 g) | 1 g | 52 | 0.1 g | 13.2 g |
| 100 g | 0.8 g | 42 | 0.1 g | 10.7 g |
| 1 oz (28 g) | 0.2 g | 12 | 0 g | 3 g |
Values computed from USDA per-100 g data (FDC 174673, SR Legacy). raw.
If you searched “protein in grapefruit,” the short answer is that there is almost none. A realistic serving — half a medium grapefruit (123 g) — carries only about 0.9 g of protein for roughly 52 calories, which is 0.8 g per 100 g. That is a trace, the same as nearly every fruit. Grapefruit is a citrus fruit built around vitamin C and water, not amino acids, so the honest way to think about it is as a refreshing, low-calorie fruit rather than anything that moves your protein total.
Why grapefruit isn’t a protein source
The scale tells the whole story. At 0.8 g per 100 g, even a whole grapefruit gives you only about 2 g of protein, and you would need to eat several of them to match the protein in a single egg. So while grapefruit technically contains a little protein, it contributes essentially nothing toward a daily protein goal. The accurate framing is simple: grapefruit is a fruit, and fruit is not where protein comes from.
There is no quality angle worth dwelling on, either. Like most fruit, grapefruit is low in several essential amino acids, but the quantity is so small that completeness never becomes the deciding factor — there just is not enough protein for it to matter.
What grapefruit is genuinely great at
Set protein aside and grapefruit is an easy fruit to recommend. Half a grapefruit delivers a large share of the day’s vitamin C, plus fiber, potassium, and — in the pink and red varieties — the antioxidant lycopene, all for about 52 calories. That low-calorie, high-water profile makes it a genuinely refreshing way to start a meal. One practical caution worth flagging: grapefruit can interact with several common medications, so check with a pharmacist if you take prescription drugs.
The smart play is to pair grapefruit with a real protein rather than expecting it to provide any. Add grapefruit segments to a breakfast anchored by eggs or Greek yogurt, or serve it alongside a meal where chicken breast or fish carries the protein and the grapefruit carries the vitamin C and brightness. For the daily protein number your fruit is rounding out, see our guide on how much protein per day.
Frequently Asked Questions
How much protein is in grapefruit?
About 0.9 g of protein in half a medium grapefruit (123 g), which is 0.8 g per 100 g (USDA FDC 174673). That half-fruit is only around 52 calories. Like nearly all fruit, grapefruit carries just a trace of protein — the number is too small to count toward a daily target.
Is grapefruit a good source of protein?
No. At under 1 g per half, grapefruit is not a protein source in any practical sense — you would need to eat several whole grapefruits to approach the protein in one egg. Grapefruit's value is vitamin C, hydration, and low-calorie volume, not protein.
How much protein is in a whole grapefruit?
A whole medium grapefruit is about 246 g, so roughly 2 g of protein for around 103 calories. Even the full fruit stays around 2 g — useful context, but still far too little to lean on as a protein source. Treat grapefruit as a fruit, and get your protein elsewhere.
Is grapefruit protein complete?
It is not a meaningful protein source either way, so completeness is largely beside the point. Like most fruit, grapefruit is low in several essential amino acids, but with under 1 g per serving the quantity is the limiting factor long before amino-acid profile is.
What is grapefruit actually good for nutritionally?
Vitamin C — half a grapefruit covers a large share of the day's needs — plus fiber, potassium, and the antioxidant lycopene in pink and red varieties, all for about 52 calories. It is a refreshing, low-calorie fruit. One caution: grapefruit can interact with certain medications, so check with a pharmacist if you take prescription drugs.
When was this data last verified?
2026-06-04, against USDA FoodData Central FDC 174673 (Grapefruit, raw, pink and red, all areas; SR Legacy). We re-verify reference pages periodically and update when USDA revises its underlying data.
Whole-food values are USDA reference data and are not assigned a Labelgrade — that score is for branded packaged products, where ingredients and added sugar/sodium actually vary. See our methodology and how much protein you need per day.