Also known as: WPH, Hydrolysed whey, Pre-digested whey, Whey peptides
Muscle & RecoveryStrong evidence
Whey partially broken down into shorter peptides before you drink it. Absorbs faster, costs considerably more, tastes worse, and makes almost no practical difference for most people.
Typical dose
20.0–40.0 g per day
Any time; strongest case is straight after damaging training
What it is
Whey hydrolysate is whey protein that has been treated with enzymes to break some of the peptide bonds, effectively doing part of the digestion before you drink it.
The extent of that breakdown is expressed as degree of hydrolysis. Lightly hydrolysed products are close to isolate; heavily hydrolysed ones are noticeably different and considerably more bitter.
That bitterness is the practical catch. Hydrolysis releases peptides that taste genuinely unpleasant, which is why hydrolysate products are heavily flavoured and why many blends use only a small proportion of it for label appeal rather than effect.
How it works
Shorter peptides are absorbed faster than intact protein, producing a quicker and slightly higher rise in blood amino acids. Some di- and tripeptides are absorbed via transporters that whole proteins cannot use.
The leucine content and overall amino acid profile are unchanged, since hydrolysis breaks bonds rather than removing anything. It is the same protein arriving sooner.
The obvious question is whether arriving sooner matters. Whey is already fast, peaking within about an hour, and muscle protein synthesis responds over several hours. Shaving minutes off an already rapid process has a small ceiling on how much it can add.
What the evidence shows
The faster absorption is well demonstrated. Studies consistently show quicker amino acid appearance in blood from hydrolysate than from intact whey.
Whether that translates into better outcomes is much less clear. Trials comparing hydrolysate with isolate or concentrate on muscle mass and strength have generally found no meaningful difference when total protein is matched.
There is somewhat better evidence for reduced muscle soreness and faster recovery of force after damaging exercise, which is the more defensible reason to choose it. For general muscle building, the premium is difficult to justify.
Dosing
Serving guidance is the same as any whey: 20 to 40 g of protein, supplying 2.5 to 3 g of leucine.
If you buy it, the situation where it makes most sense is immediately after damaging training, where the recovery evidence is strongest, or where digestive comfort is a problem with intact whey.
Check the proportion in blends. Many products list hydrolysate on the label while using it as a minority component, because it is expensive and unpleasant. If it is third or fourth in the ingredient list, you are paying for the word rather than the protein.
At a glance
Common forms
Whey hydrolysate, Partially hydrolysed whey, Within blended protein powders, Clear whey isolate
Half-life / duration
Amino acids peak in blood within 30-45 minutes
Timing
Any time; strongest case is straight after damaging training
Competition status
Permitted — not on the WADA Prohibited List
Category
Muscle & Recovery
Safety and side effects
Whey hydrolysate is well tolerated and often better tolerated than intact whey by people with digestive sensitivity, since some of the work is already done.
Milk allergen declaration still applies. Hydrolysis reduces but does not eliminate the allergenic potential of milk proteins, and hydrolysate is not a safe option for anyone with a genuine milk allergy.
The taste is the main practical complaint. Heavily hydrolysed products are bitter enough that some people cannot drink them regardless of flavouring.
Who should avoid it
Milk allergen declaration applies; hydrolysis reduces but does not eliminate allergenic potential, so it is not safe with a genuine milk allergy. Not suitable for vegans. Speak to your doctor about protein intake if you have been told your kidneys are not working normally.
This entry is provided for information only. Food supplements should not be used as a substitute for a varied and balanced diet and a healthy lifestyle. Consult a qualified healthcare professional before use if you are pregnant, breastfeeding, taking medication or under medical supervision.
