Radiation-induced sensitivity loss of LiF:Mg,Ti and LiF:Mg,Cu,P has been studied for individually deconvoluted peaks over the dose range 1–5000Gy. The recovery of LiF:Mg,Ti sensitivity by extending the time of annealing at 400∘C was also investigated. The main peaks 4 and 5 of LiF:Mg,Ti were found to be the most resistant to radiation, with no loss of sensitivity observed up to doses of 10Gy. At the highest dose of 5kGy and following the standard annealing procedure of 1h at 400∘C, the sensitivity is reduced to less than half of the value at low doses, for all peaks. Extending the annealing time leads to partial recovery of detector sensitivity. Again, this effect is the strongest for peaks 4 and 5, which restored completely their sensitivity after 11h of annealing at 400∘C. Sensitivity loss after doses higher than 100Gy appears to be irreversible and even 21h of annealing at 400∘C did not recover the original sensitivity.For LiF:Mg,Cu,P the 270∘C/10min+240∘C/60min annealing cycle was applied. Surprisingly, we found that LiF:Mg,Cu,P is more resistant to radiation than LiF:Mg,Ti—we observed no decrease of sensitivity after pre-doses of up to 100Gy. Moreover, we observed no change of the glow-curve shape after pre-doses of up to 1kGy, suggesting that the loss of sensitivity is not a result of radiation damage of trapping centres, but some other processes.